<PAGE>


    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 17, 2001
                                                             FILE NO. 333-______

===============================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                          ----------------------------

                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                          ----------------------------

                                  IBASIS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)


           DELAWARE                                            04-3332534
(STATE OR OTHER JURISDICTION OF                             (I.R.S. EMPLOYER
 INCORPORATION OR ORGANIZATION)                            IDENTIFICATION NO.)


                     20 SECOND AVENUE, BURLINGTON, MA 01803
               (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES) (ZIP CODE)

                          ----------------------------

     SHARES OF RESTRICTED STOCK ORIGINALLY ISSUED OR TO BE ISSUED UNDER THE

     PRICEINTERACTIVE, INC. AMENDED AND RESTATED 2000 RESTRICTED STOCK PLAN

           ASSUMED BY IBASIS, INC. IN CONNECTION WITH THE ACQUISITION
                            OF PRICEINTERACTIVE, INC.

                            (FULL TITLE OF THE PLAN)

                          ----------------------------

                                   OFER GNEEZY
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                  iBasis, Inc.
                                20 Second Avenue
                              Burlington, MA 01803
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (781) 505-7500
           TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE

                          ----------------------------

                                   COPIES TO:

                             JOHAN V. BRIGHAM, ESQ.
                                BINGHAM DANA LLP
                               150 Federal Street
                              Boston, MA 02110-1726
                                 (617) 951-8000

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>

================================================================================================================================
                 TITLE OF                 AMOUNT TO BE      PROPOSED MAXIMUM            PROPOSED MAXIMUM           AMOUNT OF
        SECURITIES TO BE REGISTERED        REGISTERED    OFFERING PRICE PER SHARE    AGGREGATE OFFERING PRICE   REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
<S>                                      <C>             <C>                         <C>                        <C>

   Common Stock,  $0.01 par value per
   share...............................     987,262            $1.95 (1)               $1,925,160.90 (1)           $482.00
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

(1)      Estimated solely for the purpose of determining the registration fee.
         Calculated in accordance with Rule 457(c), based on the offering of up
         to 987,262 shares at a purchase price of $1.95 per share, which is the
         average of high and low prices reported on the Nasdaq National Market
         quotation system on August 10, 2001. It is not known how many of these
         shares will be sold under this Registration Statement or at what price
         these shares will be sold.

===============================================================================

<PAGE>


                               P R O S P E C T U S

                                 987,262 SHARES
                                  IBASIS, INC.

                                  COMMON STOCK


         Selling stockholders identified or described in this prospectus may
sell up to 987,262 shares of common stock of iBasis, Inc. iBasis will not
receive any of the proceeds from the sale of shares by the selling stockholders.
iBasis' common stock is listed on the Nasdaq National Market quotation system
under the symbol "IBAS". On August 10, 2001, the closing price of the common
stock, as reported on Nasdaq, was $1.90 per share.

         THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS
THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.

         The selling stockholders may sell the shares of common stock described
in this prospectus in public or private transactions at prevailing market
prices, or at privately negotiated prices. The selling stockholders may sell
shares directly to purchasers or through brokers or dealers. Brokers or dealers
may receive compensation in the form of discounts, concessions or commissions
from the selling stockholders. More information is provided in the section
titled "Plan of Distribution."



                 The date of this prospectus is August 17, 2001.


<PAGE>


                       WHERE YOU CAN GET MORE INFORMATION

         You should rely only on the information contained in this document or
to which we have referred you. We have not authorized anyone to provide you with
information that is different. This prospectus is not an offer to sell, or a
solicitation of an offer to buy, any securities other than the shares of common
stock to which it relates, or an offer of these shares of common stock to any
person in any jurisdiction in which such offer is unlawful. The information
contained in this document may only be accurate as of the date of this document.

         This prospectus constitutes part of a registration statement filed by
iBasis with the Securities and Exchange Commission under the Securities Act of
1933. This prospectus does not contain all of the information set forth in the
registration statement, since we have omitted some parts in accordance with the
SEC's rules and regulations. For further information about iBasis and the shares
being offered by this prospectus, please refer to the registration statement and
to its exhibits. Copies of the registration statement may be inspected, without
charge, at the offices of the SEC, or obtained at prescribed rates from the
public reference facilities of the SEC at the address set forth below.

         iBasis files annual, quarterly and special reports, proxy statements
and other information with the SEC pursuant to the information requirements of
the Securities Exchange Act of 1934. You may read and copy any document filed by
us at the public reference facilities of the SEC located at 450 Fifth Street
N.W., Washington, D.C. 20549. You may obtain information on the operation of the
SEC's public reference facilities by calling the SEC at 1-800-SEC-0330. You can
also access copies of this material electronically on the SEC's home page on the
Web at http://www.sec.gov. iBasis' common stock is traded on the Nasdaq National
Market System, and information concerning us is also available for inspection at
the offices of the Nasdaq National Market, Reports Section, 1735 K Street, N.W.,
Washington, DC 20006.

         The SEC permits us to "incorporate by reference" the information that
we file with them, which means that we can disclose important information to you
by referring you to those documents. We incorporate by reference the documents
listed below and any future filings we will make with the SEC under Section
13(a), 13(c), 14 or 15(d) of the Securities Exchange Act prior to the filing of
a post-effective amendment that indicates that all securities offered by our
registration statement have been sold or that deregisters all of our securities
then remaining unsold:

1.       our annual report on Form 10-K filed on February 26, 2001 for the year
         ended December 31, 2000;

2.       our current report on Form 8-K filed on March 14, 2001;

3.       our quarterly report on Form 10-Q filed on August 14, 2001; and

4.       the description of our common stock contained in our registration
         statement filed with the SEC on August 24, 1999 under Section 12(g) of
         the Securities Exchange Act, including any amendment or report filed
         for the purpose of updating such description.

         Any statement in the documents incorporated by reference in this
prospectus shall be deemed to be modified or superseded for purposes of this
prospectus to the extent that a statement contained in this prospectus modifies
or supersedes the statement. Any statement that is so modified or superseded
shall not be deemed, except as modified or superseded, to constitute a part of
this prospectus.

         You may obtain without charge, upon written or oral request, a copy of
(1) any of the documents incorporated by reference in this prospectus, but not
exhibits to these documents, and (2) copies of all reports, proxy statements and
other communications distributed by iBasis to its security holders generally,
but not to the extent you have already received these reports, proxy statements
and other communications. You should address requests to iBasis, Inc.,
Attention: Investor Relations, 20 Second Avenue, Burlington, Massachusetts
01803, (781) 505-7500.


<PAGE>


                           FORWARD-LOOKING STATEMENTS

         This prospectus contains "forward-looking statements" within the
meaning of Section 27A of the Securities Act and Section 21E of the Exchange
Act. We intend the forward-looking statements to be covered by the safe harbor
for forward-looking statements in these sections. These forward-looking
statements include, without limitation, statements about our market opportunity,
strategies, competition, expected activities, expected profitability and
investments as we pursue our business plan, and the adequacy of our available
cash resources. These forward-looking statements are usually accompanied by
words such as "believe," "anticipate," "plan," "seek," "expect," "intend" and
similar expressions. The forward-looking information is based on various factors
and was derived using numerous assumptions.

         Forward-looking statements necessarily involve risks and
uncertainties, and our actual results could differ materially from those
anticipated in the forward-looking statements due to a number of factors,
including those set forth below under "Risk Factors" and elsewhere in this
prospectus and in the information incorporated by reference herein. The
factors set forth below under "Risk Factors" and other cautionary statements
made in or incorporated by reference into this prospectus should be read and
understood as being applicable to all related forward-looking statements
wherever they appear in this prospectus. The forward-looking statements
contained in this prospectus represent our judgment as of the date of this
prospectus. iBasis cautions readers not to place undue reliance on these
statements. We undertake no obligation to update publicly any forward-looking
statements for any reason, even if new information becomes available or other
events occur in the future.

                                  RISK FACTORS

         ANY INVESTMENT IN OUR SHARES OF COMMON STOCK INVOLVES A HIGH DEGREE
OF RISK. YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED BELOW, WHICH WE
BELIEVE ARE ALL THE MATERIAL RISKS TO OUR BUSINESS, INCLUDING THE BUSINESS OF
PRICEINTERACTIVE, INC. OF RESTON, VIRGINIA, WHICH WE ACQUIRED FEBRUARY 27,
2001 AND WHICH IS NOW CALLED OUR SPEECH SOLUTIONS LINE OF BUSINESS, TOGETHER
WITH THE INFORMATION CONTAINED ELSEWHERE IN OR INCORPORATED BY REFERENCE INTO
THE PROSPECTUS, BEFORE YOU MAKE A DECISION TO INVEST IN OUR COMPANY.

                         RISKS RELATED TO OUR OPERATIONS

WE HAVE A LIMITED OPERATING HISTORY UPON WHICH TO BASE YOUR INVESTMENT DECISION,
AND YOU MAY INACCURATELY ASSESS OUR PROSPECTS FOR SUCCESS.

We were incorporated in August 1996 and first began to offer commercial services
in May 1997. Due to our limited operating history, it is difficult for us to
predict future results of operations both for our core business and our enhanced
service offerings. Moreover, we cannot be sure that we have accurately
identified all of the risks to our business, especially because we use new, and
in many cases, unproven technologies and provide new services, the technical
implementation of which on a commercial scale, and widespread commercial
acceptance of, is yet unproven. As a result, our past results and rates of
growth may not be meaningful indicators of our future results of operations.
Also, your assessment of the prospects for our success may prove inaccurate.


WE HAVE A HISTORY OF OPERATING LOSSES AND MAY NEVER BECOME PROFITABLE.

During 2000, we incurred a net loss of $62.3 million. As of June 30, 2001, we
had an accumulated deficit of $210 million. We expect to continue to incur
operating losses and negative cash flows as we incur significant operating
expenses and make capital investments in our business. Our future profitability
will depend on our being able to deliver calls over our network at a cost to us
that is less than what we are able to charge for our calls, and utilize our
network to deliver new, enhanced services on a profitable basis. Our costs to
deliver calls are dependent on a number of factors, including the countries to
which we direct calls and whether we are able to use the Internet, rather than
another component of our network or more expensive back-up networks, to deliver
calls. The prices that we are able to charge to deliver calls over our network
vary, based primarily on the prices currently prevailing in the international
long distance carrier market to specific countries. While we are currently able
to terminate a substantial number of the calls carried over our network
profitably on an operating basis, we have been unable to


<PAGE>

operate our entire network profitably on an operating basis for sustained
periods of time. Our ability to deliver new services or capabilities like
unified communications, our Speech Solutions offerings and other new services,
also depends on a variety of factors. Unified messaging, for which we use the
brand name VoCore(TM), allows our customers to offer end-users voicemail, email,
and faxes accessible from a variety of devices, including telephones and
personal computers. We have only begun to recognize revenue from VoCore as of
May, 2001. Our SpeechPort service offering has achieved only relatively small
amounts of revenue to date. It may take longer than we expect to gain acceptance
by customers for these services or for providing these services through our
network. In addition, we may be unable to make effective use of the technology
we employ, scale the service for wide use, or leverage our network
infrastructure adequately to take advantage of possible economies of scale. We
may not ever generate sufficient revenues, or reduce costs to the extent
necessary, to permit us to achieve profitability. Even if we do become
profitable, we may not sustain or increase profitability on a quarterly or
annual basis in the future.


FLUCTUATIONS IN OUR QUARTERLY RESULTS OF OPERATIONS THAT RESULT FROM VARIOUS
FACTORS INHERENT IN OUR BUSINESS MAY CAUSE THE MARKET PRICE OF OUR COMMON STOCK
TO FALL.

Our revenue and results of operations have fluctuated and may continue to
fluctuate significantly from quarter to quarter in the future due to a number of
factors, many of which are not in our control, including, among others:

o        the amount of Internet Telephony traffic we are able to sell to our
         customers, and their decisions on whether to route traffic over our
         network;

o        our ability to generate revenues from the delivery of enhanced services
         like VoCore, the Speech Solutions offerings or new services, that are
         appealing to the market;

o        pricing pressure in the international long distance market;

o        the percentage of traffic that we are able to carry over the Internet,
         or over our dedicated international private circuit lines, rather than
         over the more costly traditional public-switched telephone network;

o        loss of arbitrage opportunities resulting from declines in
         international settlement rates or tariffs;

o        our ability to negotiate lower termination fees charged by our local
         providers if our pricing deteriorates;

o        our continuing ability to negotiate competitive costs to interconnect
         our network with those of other carriers;

o        capital expenditures required to expand or upgrade our network;

o        changes in call volume among the countries to which we complete calls;

o        the portion of our total traffic that we carry over more attractive
         routes could fall, independent of route-specific price, cost or volume
         changes;

o        technical difficulties or failures of our network systems or
         third-party delays in expansion or provisioning system problems;

o        loss of major customers because of bankruptcies, or our inability to
         collect amounts owed to us; and

o        currency fluctuations in countries where we operate.

Because of these factors, you should not rely on quarter-to-quarter comparisons
of our results of operations as an indication of our future performance. It is
possible that, in future periods, our results of operations will be
significantly lower than the estimates of public market analysts and investors.
A discrepancy of this nature could cause the price of our common stock to
decline significantly.


WE MAY NEVER GENERATE SUFFICIENT REVENUE TO ATTAIN PROFITABILITY IF
COMMUNICATIONS SERVICE PROVIDERS AND OTHERS ARE RELUCTANT TO USE OUR SERVICES OR
DO NOT USE OUR SERVICES, INCLUDING ANY ENHANCED SERVICES, IN SUFFICIENT VOLUME.

If the market for Internet telephony and other new services does not develop as
we expect, or develops more slowly than expected, our business, financial
condition and results of operations will be materially and adversely affected.
Our customers may be reluctant to use our Internet telephony services for a
number of reasons, including:

o        perceptions that the quality of voice transmitted over the Internet is
         low;

o        perceptions that Internet telephony is unreliable;

o        our inability to deliver traffic over the Internet with significant
         cost advantages; and

o        development of their own capacity on routes served by us.

<PAGE>


Our potential customers for our new services may be reluctant to use these
services as a result of perceptions that our enhanced services are unnecessary,
too expensive, ineffective, or not appealing to their end-users or client base.
The growth of our core business depends on carriers and other communications
service providers generating an increased volume of international voice and fax
traffic and selecting our network to carry at least some of this traffic. If the
volume of international voice and fax traffic fails to increase, or decreases,
and these third-parties do not employ our network, our ability to become
profitable will be materially and adversely affected. In addition, we cannot
assure investors that communications service providers and their end-users and
others will be receptive to, and subscribe to, unified communications services,
or any other enhanced services that we elect to deploy on our network. Any
perceived problems with the reliability or functionality of any new services
that we offer could discourage communications service providers or others from
offering these services to their customers. In addition, the development of new
capabilities, such as VoCore and other new services, may require substantial
additional capital expenditures to be made well in advance of generating any
revenue from these services or demonstrating any market acceptance of these
services. If carriers and other communications service providers do not employ
our network to offer any new services to their customers, or if their customers
do not subscribe for the services when offered, our results of operations will
be materially adversely affected. We cannot assure you that end-users will
continue to purchase services from our customers or that our customers will
maintain a demand for our services.


WE MAY NOT BE ABLE TO SUCCESSFULLY INTEGRATE THE SPEECH SOLUTIONS OPERATIONS AND
BUSINESS TO MAXIMIZE THE POTENTIAL BENEFITS OF THE MERGER.

After the merger with PriceInteractive,Inc., we have tried to preserve and
increase the potential benefits that may result from the combined companies.
These benefits include, among others, expanded and complementary product
offerings, an increased sales force, greater market exposure, and new technology
and engineering and development personnel. Achieving these benefits from the
merger will depend in part on the integration of our technology, operations and
personnel in a timely and efficient manner so as to minimize the risk that the
merger will result in the loss of market opportunity or key employees or the
diversion of the attention of management.

Among some of the challenges we continue to face are:

o        operational or technological procedures that may not be compatible;

o        significant diversion of management's time and attention that could
         otherwise be spent on attracting business prospects, enhancing services
         or other matters;

o        developing long-term strategies in dynamic business cultures and
         different markets;

o        maintaining key personnel without which it could be difficult to
         complete existing projects or undertake new projects; and

o        increased costs associated with the integration of the two companies.

In addition, we cannot assure you that our businesses will achieve revenues,
specific net income or loss levels, efficiencies or synergies that justify the
merger or that the merger will result in increased earnings for the combined
company in any future period. Further, the combined company may experience
slower rates of growth as compared to historical rates of growth of them
independently.


WE MAY FACE QUALITY AND CAPACITY PROBLEMS UPON FAILURES BY THIRD PARTIES.

VENDORS. Our Internet Telephony line of business relies upon third-party vendors
to provide us with the equipment and software that we use to transfer and
translate calls from traditional voice networks to the Internet, and vice versa.
For example, we purchase substantially all of our Internet telephony equipment
from Cisco Systems. Our Speech Solutions and messaging lines of business rely
upon third-party vendors to provide speech recognition and other technologies.
We cannot assure you that we will be able to continue purchasing this equipment
and software from our vendors on acceptable terms, if at all. If we become
unable to purchase from these vendors the software and equipment that we
require, we may not be able to maintain or expand our offerings to accommodate
growth. As a result, we may be unable to increase revenues sufficiently to
become profitable. See also "Strategic Relationships" below.


<PAGE>

PARTIES THAT MAINTAIN PHONE AND DATA LINES. Our business model depends on the
availability of the Internet and traditional telephone networks to transmit
voice and fax calls, dial-up access to such networks, and to provide other
enhanced services. Third parties maintain and, in many cases, own these networks
and other components that comprise the Internet. Some of these third parties are
national telephone companies. They may increase their charges for using these
lines at any time and decrease our profitability. They may also fail to maintain
their lines properly and disrupt our ability to provide service to our
customers. Sometimes local governments may suspend or interrupt the access of
these lines. Any failure by these third parties to maintain these lines and
networks that leads to a material disruption of our ability to complete calls or
provide other services could discourage our customers from using our network or
enhanced services, which could have the effect of delaying or preventing our
ability to become profitable.

LOCAL COMMUNICATIONS SERVICE PROVIDERS. We maintain relationships with local
communications service providers in many countries for our Internet Telephony
business, some of whom own the equipment that translates voice to data in that
country. We rely upon these third parties both to provide lines over which we
complete calls and to increase their capacity when necessary as the volume of
our traffic increases. There is a risk that these third parties may be slow, or
fail, to provide capacity, which would affect our ability to complete calls to
those destinations. We cannot assure you that we will be able to continue our
relationships with these local service providers on acceptable terms, if at all.
Because we rely upon entering into relationships with local service providers to
expand into additional countries, we cannot assure you that we will be able to
increase the number of countries to which we provide service. We also may not be
able to enter into relationships with enough overseas local service providers to
handle increases in the volume of calls that we receive from our customers.
Finally, any technical difficulties that these providers suffer would affect our
ability to transmit calls to the countries that those providers help us serve.

STRATEGIC RELATIONSHIPS. We depend in part on our strategic relationships to
expand our distribution channels and develop and market our services. In
particular, we depend in large part on our joint marketing and product
development efforts with Cisco Systems to achieve market acceptance and brand
recognition in some markets. Our VoCore service relies on technology and
services from companies such as OpenWave, EMC and Hewlett-Packard. Strategic
relationship partners may choose not to renew existing arrangements on
commercially acceptable terms, if at all. In addition, our Speech Solutions
line of business also depends in part on its strategic relationships with
SpeechWorks International, Inc. and MicroStrategy. In general, if we lose
these or other key strategic relationships, or if we fail to maintain or
develop new relationships in the future, our ability to expand the scope and
capacity of our network and services provided, and to maintain
state-of-the-art technology, would be materially adversely affected. New
services will also rely on key strategic relationships, which will be subject
to the same considerations.

THE MARKET DEMAND FOR VOCORE, SPEECH SOLUTIONS, AS WELL AS ANY NEW SERVICES MAY
NOT DEVELOP AS ANTICIPATED, WHICH WOULD SUBSTANTIALLY IMPEDE OUR ABILITY TO
GENERATE REVENUES.

Our future financial performance depends in part on growth in demand for
VoCore, Speechport speech recognition services and products, and other
services including conferencing. If the market for these services and
products does not develop or if we are unable to capture a significant
portion of that market, either directly or through our partners, our
results of operations will be adversely affected. The markets for unified
messaging and voice application services and products is relatively new and
evolving. The adoption of these services and products could be hindered by
the perceived cost, quality and reliability of these new technologies, as
well as the reluctance among businesses that have invested substantially in
legacy equipment that provide traditional email, voicemail and/or
touch-tone-based, interactive voice response and other systems. The continued
development of the market for our enhanced services and products will depend
upon the:

o        widespread adoption of voice-driven applications by businesses for use
         in conducting transactions and managing relationships with their
         customers;

o        commitments by businesses and carriers of outsourced hosted solutions
         for messaging, call centers, and other applications such as
         conferencing;

o        widespread adoption of solutions to unify a variety of communications
         modes through one solution;

<PAGE>

o        consumer acceptance of these applications; and

o        continuing improvements in hardware and software technology that may
         reduce the cost and improve the performance of voice solutions.

The market for speech-activated services is new and potential industry
standards, such as VoiceXML, have not yet matured. If multiple standards are
adopted, we may need to support them, which would require additional time and
resources, and could negatively impact revenue and margins. If we fail to meet
subscriber expectations, even if demand for VoCore and new voice application
services grows, the marketability of VoCore and any other service could be
materially reduced.


THE QUALITY OF SPEECH APPLICATIONS OVER AN IP NETWORK HAS NOT YET BEEN FULLY
PROVEN AND FAILURES BY VOICE SITE PROVIDERS TO ADOPT THESE APPLICATIONS MAY HARM
OUR FUTURE RESULTS OF OPERATIONS.

Speech applications, such as our SpeechPort, have not been extensively tested on
Internet Protocol infrastructures. If performance and accuracy of speech
services are negatively affected by a particular IP infrastructure, the
commercial acceptance of these applications by voice site providers on that
infrastructure will be low. Failure by voice site providers to adopt these
applications may have a material negative impact on our results of operations,
which could cause our stock price to decline. As an international company,
iBasis is also dependent upon the further development of text-to-speech and
speech recognition applications in multiple languages.


OUR CUSTOMERS MAY REQUIRE A LONGER SALES AND IMPLEMENTATION CYCLE OR COULD NOT
BE READY TO COMMIT TO OUTSOURCED SOLUTIONS, WHICH COULD NEGATIVELY AFFECT OUR
REVENUE PLANS.

If actual sales and development cycles for our enhanced offerings are
substantially longer than anticipated, revenue targets would not be met.
Additionally, revenue targets may not be met if businesses and our potential
customers delay their decisions to adoptand implement outsourced solutions for
speech-enabled applications. The failure or lack of effective third-party
technologies and services could limit our ability to generate revenues. Some of
our enhanced service offerings are dependent on technology developed by third
parties. These technologies include:

o        email servers that process both email messages and voicemail messages;

o        software that converts text to speech;

o        speech recognition software;

o        billing system software;

o        conferencing software; and

o        network operations center servers, routers and other equipment.

We will continue to incorporate third-party technologies in future unified
communications and speech application services and products. We have limited
control over whether or when these third-party technologies will be enhanced. In
addition, our competitors may acquire interests in these third parties or their
technologies, which may render the technology unavailable to us. If a third
party fails or refuses to timely develop, license or support technology
necessary to our services or products, market acceptance of our services or
products could be adversely affected. Moreover, if these third-party
technologies fail or otherwise prove to be not viable, it may have a significant
impact on our ability to provide our services and/or to generate revenues. In
addition, we rely and will continue to rely on services supplied by third
parties such as telecommunications, Internet access and electrical power for
services hosted in our network operations center. If these third-party services
fail to meet industry standards for quality and reliability, market acceptance
of our services could be adversely affected.


<PAGE>

WE MAY NOT BE ABLE TO SUCCEED IN THE INTENSELY COMPETITIVE MARKET FOR OUR
VARIOUS SERVICES.

The market for Internet voice, fax and other enhanced services is extremely
competitive and will likely become more competitive. Internet protocol and
Internet telephony service providers, such as GRIC Communications and ITXC
Corp., route traffic to destinations worldwide and compete directly with us.
Also, Internet telephony service providers, such as Net2Phone, that presently
focus on retail customers, may in the future enter our market and compete with
us. These retail-oriented carriers also provide PC-to-PC services at very low
prices or for free. Perceived competition with this market segment could drive
our prices down. In addition, major telecommunications carriers, such as AT&T,
Deutsche Telekom, MCI WorldCom and Qwest Communications, have all entered or
announced plans to enter the Internet telephony market. In particular, AT&T
invested over $2 billion in Net2Phone in April. We also face competition from
other companies who offer unified communications and speech recognition
applications. We directly compete at the wholesale level with a number of other
unified communications providers such as deltathree.com, Orchestrate, Tornado
Development, and uReach. Some of the competition (e.g., deltathree.com and
Tornado Development) sell unified communications directly to end users in
addition to selling at the wholesale level. Furthermore, voice portal companies
such as TellMe and BeVocal may in the future develop business models that
compete directly with our Speech Solutions business. Many of these companies are
larger than we are and have substantially greater managerial and financial
resources than we do. Intense competition in our markets can be expected to
continue to impose downward pressure on prices and adversely affect our
profitability. We cannot assure you that we will be able to compete successfully
against our competitors and we may lose customers or fail to grow our business
as a result of this competition.


WE ARE SUBJECT TO DOWNWARD PRICING PRESSURES ON OUR WHOLESALE INTERNATIONAL
INTERNET TELEPHONY SERVICES AND A CONTINUING NEED TO RENEGOTIATE OVERSEAS RATES,
WHICH COULD DELAY OR PREVENT OUR PROFITABILITY.

As a result of numerous factors, including increased competition and global
deregulation of telecommunications services, prices for international long
distance calls have been decreasing. This downward trend of prices to end users
has caused us to lower the prices we charge communications service providers for
call completion on our network. If this downward pricing pressure continues, we
cannot assure you that we will be able to offer Internet telephony services at
costs lower than, or competitive with, the traditional voice network services
with which we compete. Moreover, in order for us to lower our prices, we have to
renegotiate rates with our overseas local service providers who complete calls
for us. We may not be able to renegotiate these terms favorably enough, or fast
enough, to allow us to continue to offer services in a particular country on a
cost-effective basis. The continued downward pressure on prices and our failure
to renegotiate favorable terms in a particular country would have a material
adverse effect on our ability to operate our network and Internet telephony
business profitably.


A VARIETY OF RISKS ASSOCIATED WITH OUR INTERNATIONAL OPERATIONS COULD MATERIALLY
ADVERSELY AFFECT OUR BUSINESS.

Because we provide many of our services internationally, we are subject to
additional risks related to operating in foreign countries. In particular, in
order to provide services and operate facilities in some countries, we have
established subsidiaries or other legal entities. Associated risks include:

o        unexpected changes in tariffs, trade barriers and regulatory
         requirements relating to Internet access or Internet telephony, or
         enhanced services;

o        economic weakness, including inflation, or political instability in
         particular foreign economies and markets;

o        difficulty in collecting accounts receivable;

o        compliance with tax, employment immigration and labor laws for
         employees living and traveling abroad;

o        foreign taxes including withholding of payroll taxes; and

o        foreign currency fluctuations, which could result in increased
         operating expenses and reduced revenues; and other obligations incident
         to doing business or operating a subsidiary in another country.

In addition, we are subject to a variety of risks associated with the provision
of unified communications and international voice site business management, any
of which could negatively affect our business. These risks include providing
easy telephone access to The iBasis Network(TM) and relying on third party
vendors to create and


<PAGE>

refine different language models for each particular language or dialect.
These language models are required to create versions of our products that
allow end users to speak the local language or dialect and be understood and
authenticated. If vendors fail to develop localized versions of our products,
our ability to address international market opportunities and to grow our
business will be limited. These and other risks associated with our
international operations may materially adversely affect our ability to
attain or maintain profitable operations. A significant portion of our
revenue has historically been generated by delivering calls to Asian, Middle
Eastern and Latin American countries. Political or economic instability in
countries to which we deliver substantial volumes of traffic could lead to
difficulties in completing calls through our regional service providers or
decreased call volume to these countries.

IF WE ARE NOT ABLE TO KEEP UP WITH THE RAPID TECHNOLOGICAL CHANGE IN A
COST-EFFECTIVE WAY, THE RELATIVE QUALITY OF OUR SERVICES COULD SUFFER.

The technology upon which our services depend is changing rapidly. Significant
technological changes could render the hardware and software that we use
obsolete, and competitors may begin to offer new services that we are unable to
offer. We must adapt to our rapidly changing market by continually improving the
responsiveness, reliability, services and features of our network and by
developing new features and applications to meet customer needs. If we are
unable to respond successfully to these developments or do not respond in a
cost-effective way, we may not be able to offer competitive services.


WE MAY NOT BE ABLE TO EXPAND AND UPGRADE OUR NETWORK ADEQUATELY AND
COST-EFFECTIVELY TO ACCOMMODATE ANY FUTURE GROWTH.

Our Internet telephony business requires that we handle a large number of
international calls simultaneously. As we expand our operations, we expect to
handle significantly more calls as well as other services. We will need to
expand and upgrade our hardware and software to accommodate increased traffic.
If we do not expand and upgrade quickly enough, we will not have sufficient
capacity to handle the traffic and growth in our operating performance would
suffer. Even with this expansion, we may be unable to manage new deployments or
utilize them in a cost-effective manner. In addition to lost growth
opportunities, any one of these failures could adversely affect customer
confidence in The iBasis Network and could result in us losing business
outright.


IF THE INTERNET DOES NOT REMAIN VIABLE AND CONTINUE TO GROW AS A MEDIUM FOR
VOICE AND FAX COMMUNICATIONS AND OTHER ENHANCED SERVICES, OUR BUSINESS WILL
SUFFER.

The technology that allows voice and fax communications, and the delivery of
other enhanced services and capabilities like VoCore and our Speech Solutions
services, over the Internet, are still in the early stages of development.

Our future success will depend in part upon the maintenance of the Internet
infrastructure, including a reliable network backbone with the necessary speed,
data capacity and security for providing reliability and timely Internet access
and services. To the extent that the Internet continues to experience increased
numbers of users, frequency of use or bandwith requirements, the Internet may
become congested and be unable to support the demands placed on it and its
performance or reliability may decline thereby impairing our ability to complete
calls and provide other services using the Internet at consistently high
quality. As a result of the Internet's capacity constraints, callers could
experience delays, errors in transmissions or other interruptions in service.
Transmitting telephone calls over the Internet, and other uses of the Internet
for our enhanced services, must also be accepted by customers as an alternative
to traditional services. Moreover, critical issues concerning the commercial use
of the Internet, including security, cost, ease of use and access, intellectual
property ownership and other legal liability issues, remain unresolved and could
materially and adversely affect both the growth of Internet usage generally and
our business in particular.

Finally, if the overall performance of the Internet is seriously downgraded by
Website attacks or other acts of computer vandalism or virus infection, our
ability to deliver our communication services over the Internet could be
adversely impacted.


<PAGE>

IF WE FAIL TO MANAGE OUR GROWTH, WE COULD LOSE CUSTOMERS.

We have grown rapidly and expect to continue to do so. In order to increase the
number of our customers and the size of our operations, we will need to improve
our administrative, accounting, operating systems and controls. We may need to
redesign several internal systems. Our attention to these matters may distract
us from other aspects of our business. Moreover, failure to implement new
systems and controls may hamper our ability to provide services to customers and
may impair the quality of our services, which could result in the loss of
customers.


OUR CASH RESERVES WOULD DECLINE SIGNIFICANTLY IF WE CANNOT COLLECT DEBTS FROM
OUR CUSTOMERS.

We generate much of our revenue from a limited number of customers. Customers
may also discontinue their use of our services at any time, and without notice.
Some of our customers have filed for bankruptcy or are in the midst of
reorganizing. Other customers have delayed payments to owed to us. We may be
unable to collect amounts due to us by these customers. Therefore, in any given
quarter, we would lose a significant amount of revenue or cash if we lost one or
more major customers or if a major customer is unable or unwilling to pay
amounts owed to us on a timely basis or at all.


WE DEPEND ON OUR KEY PERSONNEL AND MAY HAVE DIFFICULTY ATTRACTING AND RETAINING
THE SKILLED EMPLOYEES WE NEED TO EXECUTE OUR GROWTH PLANS. WE DEPEND HEAVILY ON
OUR KEY MANAGEMENT.

Our future success will depend, in large part, on the continued service of
our key management and technical personnel. If any of these individuals are
unable or unwilling to continue in their present positions, our business,
financial condition and results of operations would suffer. We do not carry
key person life insurance on our personnel. While most of our key management
has entered into employment agreements with us, these agreements do not
ensure their continued employment with us.

WE WILL NEED TO ATTRACT SKILLED PERSONNEL TO EXECUTE OUR GROWTH PLANS.

Our future success will depend, in large part, on our ability to attract, retain
and motivate highly skilled employees, particularly engineering and technical
personnel. Competition for these employees in our industry at times has been
intense. We have from time to time in the past experienced, and we expect to
continue to experience in the future, difficulty in hiring and retaining
employees with appropriate qualifications. We may not be able to retain our
employees or attract, assimilate or retain other highly qualified employees in
the future. If we do not succeed in attracting and retaining skilled personnel,
we may not be able to grow at a sufficient rate to achieve profitable
operations.


A FAILURE TO OBTAIN NECESSARY ADDITIONAL CAPITAL IN THE FUTURE ON ACCEPTABLE
TERMS COULD PREVENT US FROM EXECUTING OUR BUSINESS PLAN.

We may need additional capital or cash in the future to fund our operations,
finance investments in equipment and corporate infrastructure, expand our
network, increase the range of services we offer and respond to competitive
pressures and perceived opportunities. Cash flow from operations, and cash on
hand may not be sufficient to cover our operating expenses and capital
investment needs. We cannot assure you that additional financing will be
available on terms acceptable to us, if at all. We may pursue different
strategies of raising funds necessary to maintain or grow operations. These
strategies may include but are not limited to, bank or equipment financings,
and raising funds through equity sales or sales of assets, among other
strategies. A failure to obtain additional funding could prevent us from
making expenditures that are needed to allow us to grow or maintain our
operations. If we raise additional funds by selling equity securities, the
relative equity ownership of our existing investors could be diluted or the
new investors could obtain terms more favorable than previous investors. If
we raise additional funds through debt financing, we could incur significant
borrowing costs. The failure to obtain additional financing when required
could result in our being unable to grow as required to attain profitable
operations.

<PAGE>

THE ANTICIPATED GAINS OF OUR INVESTMENTS IN CAPITAL INFRASTRUCTURE AND IN
STRATEGIC EQUITY ACQUISITIONS MAY NEVER BE REALIZED.

We have invested heavily in overseas operations and deployed Internet central
offices in various countries around the world. Due to our ability to exchange
telephony and data traffic with major customers at fewer points, we find it is
no longer necessary to deploy such infrastructure. We have also made equity
investments in strategic partners, which have failed or are not generating the
returns that were expected. These investments may have a negative impact on our
cash and financial position. We may never be able to realize a return on these
investments.


IF WE ARE UNABLE TO PROTECT OUR INTELLECTUAL PROPERTY, OUR COMPETITIVE POSITION
WOULD BE ADVERSELY AFFECTED.

We rely on patent, trademark and copyright law, trade secret protection and
confidentiality and/or license agreements with our employees, customers,
partners and others to protect our intellectual property. Unauthorized third
parties may copy our services or reverse engineer or obtain and use information
that we regard as proprietary. End-user license provisions protecting against
unauthorized use, copying, transfer and disclosure of any licensed program may
be unenforceable under the laws of certain jurisdictions and foreign countries.
We may seek to patent software or equipment in the future. We do not know if any
of our future patent applications will be issued with the scope of the claims we
seek, if at all. In addition, the laws of some foreign countries do not protect
proprietary rights to the same extent as do the laws of the United States. Our
means of protecting our proprietary rights in the United States or abroad may
not be adequate and third parties may infringe or misappropriate our copyrights,
trademarks and similar proprietary rights. If we fail to protect our
intellectual property and proprietary rights, our business, financial condition
and results of operations would suffer. We believe that we do not infringe upon
the proprietary rights of any third party, and no third party has asserted a
material patent infringement claim against us. It is possible, however, that
such a claim might be asserted successfully against us in the future. Our
ability to provide our services depends on our freedom to operate. That is, we
must ensure that we do not infringe upon the proprietary rights of others or
have licensed all necessary rights. We have not requested or obtained an opinion
from counsel as to whether our services infringe upon the intellectual property
rights of any third parties. A party making an infringement claim could secure a
substantial monetary award or obtain injunctive relief that could effectively
block our ability to provide services in the United States or abroad. We have
received letters and other notices claiming that certain of our services may
infringe patents or other intellectual property of other parties. To date, none
of these has resulted in a material restriction on any use of our intellectual
property or has had a material adverse impact on our business. We may be unaware
of intellectual property rights of others that may, or may be claimed to, cover
our technology. Current or future claims could result in costly litigation and
divert the attention of management and key personnel from other business issues.
The complexity of the technology involved and the uncertainty of intellectual
property litigation increase these risks. Claims of intellectual property
infringement also might require us to enter into costly royalty or license
agreements to the extent necessary for the conduct of our business. However, we
may be unable to obtain royalty or license agreements on terms acceptable to us,
or at all. We also may be subject to significant damages or an injunction
against use of our proprietary or licensed systems. A successful claim of patent
or other intellectual property infringement against us could materially
adversely affect our business and profitability. We rely on a variety of
technology, primarily software that is licensed from third parties. Continued
use of this technology by us requires that we purchase new or additional
licenses from third parties. We cannot assure you that we can obtain those
third-party licenses needed for our business or that the third party technology
licenses that we do have will continue to be available to us on commercially
reasonable terms or at all. The loss or inability to maintain or obtain upgrades
to any of these technology licenses could result in delays or breakdowns in our
ability to continue developing and providing our services or to enhance and
upgrade our services.


WE MAY UNDERTAKE ADDITIONAL STRATEGIC ACQUISITIONS IN THE FUTURE AND ANY
DIFFICULTIES FROM INTEGRATING THESE ACQUISITIONS COULD DAMAGE OUR ABILITY TO
ATTAIN OR MAINTAIN PROFITABILITY.

We may acquire additional businesses and technologies that complement or augment
our existing businesses, services and technologies. Integrating any newly
acquired businesses or technologies could be expensive and time-consuming. We
may not be able to integrate any acquired business successfully. Moreover, we
may need to raise additional funds through public or private debt or equity
financing to acquire any businesses, which may result in dilution for
stockholders and the incurrence of indebtedness. We may not be able to operate
acquired businesses profitably or otherwise implement our growth strategy
successfully.


<PAGE>


                          RISKS RELATED TO OUR COMPANY

THE MARKET PRICE OF OUR SHARES MAY EXPERIENCE EXTREME PRICE AND VOLUME
FLUCTUATIONS FOR REASONS OVER WHICH WE HAVE LITTLE CONTROL.

From time to time, the stock market has experienced, and is likely to continue
to experience, extreme price and volume fluctuations. Prices of securities of
Internet-related companies have been especially volatile and have often
fluctuated for reasons that are unrelated to the operating performance of the
affected companies. The market price of shares of our common stock has
fluctuated greatly since our initial public offering and could continue to
fluctuate due to a variety of factors.


WE HAVE BEEN SERVED WITH CLASS ACTION COMPLAINTS RELATING TO OUR INITIAL PUBLIC
OFFERING.

We have been served with several class action suits that relate to our
initial public ofering and allege that the underwriters of such offering
received undisclosed compensation in connection therewith. An adverse
resolution of one or more of these lawsuits, if not covered by insurance,
would have a material adverse effect on our financial position. For more
information see also "Legal Proceedings" below.

INTERNATIONAL GOVERNMENTAL REGULATION AND LEGAL UNCERTAINTIES COULD LIMIT OUR
ABILITY TO PROVIDE OUR SERVICES OR MAKE THEM MORE EXPENSIVE.

The regulatory treatment of Internet telephony and our enhanced services
offerings outside of the United States varies widely by country. A number of
countries currently prohibit or limit competition in the provision of
traditional voice telephony services. In some of those countries, licensed
telephony carriers as well as foreign regulators have questioned our legal
authority and/or the legal authority of our partners to offer our services. We
may face similar questions in additional countries. If we are forced to suspend
or discontinue operations as a result of foreign regulatory or legal challenges,
this could substantially affect our ability to achieve profitability. Some
countries prohibit, limit or regulate how companies provide Internet telephony.
Some countries have indicated they will evaluate proposed Internet telephony
service on a case-by-case basis and determine whether to regulate it as a voice
service or as another telecommunications service, and in doing so potentially
impose subsidies or other costs on Internet telephony providers. In addition,
many countries have not yet addressed Internet telephony in legislation or
regulations. Increased regulation of the Internet and/or Internet telephony
providers, or the prohibition of Internet telephony or related services,
including our enhanced offerings, in one or more countries, could limit our
ability to provide our services or make them more expensive. Finally,
international organizations such as the International Telecommunications Union
and the European Commission are continuing to examine whether Internet telephony
should continue to be subject to light regulation. Adverse recommendations by
these bodies could also limit our ability to provide services profitably. In
addition, as we make our services available in foreign countries, and as we work
to enable sales by our customers to end-users in foreign countries, these
countries may claim that we are required to qualify to do business in that
particular country, that we are otherwise subject to regulation, including
requirements to obtain authorization, or that we are prohibited in all cases
from conducting our business in that foreign country. We currently have
subsidiaries in Argentina, Australia, Brazil, Hong Kong, Israel, Japan, Mexico,
Peru, the United Kingdom and Singapore. We are authorized to provide services in
Belgium, Canada, France, Germany, Italy, Netherlands, Peru, Singapore, Spain,
Switzerland, and the United Kingdom, and the United States. Our failure to
qualify as a foreign corporation in a jurisdiction in which we are required to
do so or to comply with foreign laws and regulations could seriously restrict
our ability to provide services in these jurisdictions, or limit our ability to
enforce contacts in that jurisdiction. Our customers also currently are, or in
the future may become, subject to these same requirements. We cannot assure you
that our customers are currently in compliance with any


<PAGE>

of these requirements or that they will be able to continue to comply with any
of these requirements. The failure of our customers to comply with applicable
laws and regulations could prevent us from being able to conduct business with
them, and would result in a loss of revenue for us. Additionally, it is possible
that countries may apply laws to transport services provided over the Internet,
including laws governing:

o        sales and other taxes, including payroll withholding applications;

o        user privacy;

o        labor and employment practices;

o        pricing controls;

o        characteristics and quality of products and services;

o        consumer protection;

o        cross-border commerce, including laws that would impose tariffs, duties
         and other import restrictions;

o        copyright, trademark and patent infringement; and

o        claims based on the nature and content of Internet materials, including
         defamation, negligence and the failure to meet necessary obligations.

If foreign governments or other bodies begin to regulate or prohibit Internet
telephony or our other services, this regulation could have a material adverse
effect on our ability to attain or maintain profitability.


THE TELECOMMUNICATIONS INDUSTRY IS SUBJECT TO DOMESTIC GOVERNMENTAL REGULATION
AND LEGAL UNCERTAINTIES THAT COULD PREVENT US FROM EXECUTING OUR BUSINESS PLAN.

While the Federal Communications Commission has tentatively decided that
information service providers, including Internet telephony providers, are
not telecommunications carriers for regulatory purposes, various companies
have challenged that decision. Some Congressional elements are dissatisfied
with the conclusions of the FCC and the FCC could impose greater or lesser
regulation on our industry. These regulations could mean imposition of
surcharges related to such things as access or universal service. We cannot
assure you that state government agencies will not increasingly regulate
Internet-related services. Increased regulation of the Internet may slow its
growth. This regulation may also negatively impact the cost of doing business
over the Internet and materially adversely affect our ability to attain or
maintain profitability. We are not licensed to offer traditional
telecommunications services in any U.S. state and we have not filed tariffs
for any service at the Federal Communications Commission or at any state
regulatory commission. Nonetheless, as more fully discussed in our Annual
Report on Form 10-K for the year ended December 31, 2000, under the caption
"Government Regulation", aspects of our operations may currently be, or
become, subject to state or federal regulations governing licensing,
universal service funding, disclosure of confidential communications or other
information, excise taxes, transactions restricted by U.S. embargo and other
reporting or compliance requirements. This regulation may also negatively
impact the cost of doing business and materially adversely affect our ability
to attain or maintain profitability.

PROVISIONS OF OUR GOVERNING DOCUMENTS AND DELAWARE LAW COULD DISCOURAGE
ACQUISITION PROPOSALS OR DELAY A CHANGE IN CONTROL.

Our certificate of incorporation and by-laws contain anti-takeover provisions,
including those listed below, that could make it more difficult for a third
party to acquire control of our company, even if that change in control may be
beneficial to stockholders:

o        our board of directors has the authority to issue common stock and
         preferred stock, and to determine the price, rights and preferences of
         any new series of preferred stock, without stockholder approval;

o        our board of directors is divided into three classes, each serving
         three-year terms;

o        our stockholders need a supermajority of votes to amend key provisions
         of our certificate of incorporation and by-laws;

o        there are limitations on who can call special meetings of stockholders;

o        our stockholders may not take action by written consent; and

o        our stockholders must provide specified advance notice to nominate
         directors or submit stockholder proposals.


<PAGE>

In addition, provisions of Delaware law and our stock option plan may also
discourage, delay or prevent a change of control of our company or unsolicited
acquisition proposals.


                               ABOUT IBASIS, INC.

         We are a provider of advanced Internet-based voice communications. We
deliver toll-quality, international voice services and provide the
infrastructure for hosted communications solutions, including unified
communications and speech-enabled content, e-commerce and customer service
applications. We were incorporated in Delaware in 1996 and our principal
executive offices are located at 20 Second Avenue, Burlington, Massachusetts
01803. Our telephone number is (781) 505-7500 and our Web site is located at
www.ibasis.net. Information contained on our Web site is not a part of this
prospectus.



<PAGE>


 THE PRICEINTERACTIVE, INC. AMENDED AND RESTATED 2000 RESTRICTED STOCK PLAN

         On February 27, 2001, PriceInteractive, Inc., a Delaware
corporation, merged with and into our wholly-owned subsidiary, iBasis Speech
Solutions, Inc. and as a result we acquired all of the outstanding capital
stock of PriceInteractive. In connection with that merger we assumed the
PriceInteractive, Inc. Amended and Restated 2000 Restricted Stock Plan and
the awards previously granted under the Plan. This prospectus is part of a
registration statement under the Securities Act of 1933 that registers the
issuance of shares of our common stock pursuant to the grant of new awards
under the plan, and the resale of shares of our common stock issued under
this plan by the recipients thereof. The common stock underlying the awards
is subject to vesting conditions and is contingent upon the recipients
continued employment with iBasis. Generally, the restrictions on the shares
of iBasis common stock subject to the plan lapse as to 50% of a holder's
shares if that employee remains an employee of iBasis as of December 31,
2001, and any remaining restrictions lapse in full on December 31, 2002, if
the employee remains an employee of iBasis on such date. The lapse of these
vesting conditions is subject to acceleration upon certain events, including
the termination of such selling stockholder's employment by iBasis without
cause. In the event that an employee is terminated, any shares of common
stock subject to the plan and held by such employee which are not accelerated
may be canceled and reissued by iBasis at the direction of the administrator
of the plan to other former employees of PriceInteractive participating in
the plan.

                              SELLING STOCKHOLDERS

         As used in this prospectus, the term "selling stockholders" includes
the holders listed below as well as an undetermined number of additional
persons who are not affiliates of iBasis who may hold up to 1,000 shares of
iBasis common stock issued under the plan.

         Because the selling stockholders may sell all or a portion of the
shares of common stock beneficially owned by them, no estimate can be given as
to the number of shares of common stock that will be beneficially owned by the
selling stockholders after this registration statement is declared effective. In
addition, the selling stockholders may have sold, transferred or otherwise
disposed of, or may sell, transfer or otherwise dispose of, at any time or from
time to time since the date on which they provided to iBasis the information
regarding the shares of common stock beneficially owned by them, all or a
portion of the shares of common stock beneficially owned by them in transactions
exempt from the registration requirements of the Securities Act.

         The following table sets forth information regarding the beneficial
ownership of the shares by the selling stockholders as of the date of this
prospectus. None of the selling stockholders owns 1% or more of the
outstanding common stock and none of the selling stockholders will hold any
shares of common stock after the offering. As of August 14, 2001 there were
approximately 45.2 million shares of common stock issued and outstanding. All
of the shares to be sold by each selling stockholder hereunder are subject to
the vesting conditions described under "The PriceInteractive Amended and
Restated 2000 Restricted Stock Plan" above.

<TABLE>
<CAPTION>

    NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
<S>                                        <C>                                   <C>

Asokan, Ramachandran                                           3,590                 3,590
Bailey, Joe                                                    2,154                 2,154
Bartolomei, David                                              4,308                 4,308
Bittner, Steve                                                44,875                44,875
Blackburn, Carrie                                              2,512                 2,512
Buckman, Deborah                                               1,436                 1,436
Callahan, Colin                                               11,128                11,128
Cooke, Todd                                                    2,512                 2,512
Costenbader, Dave                                             21,540                21,540
Covert, Fred                                                   4,308                 4,308
</TABLE>



<PAGE>

<TABLE>
<CAPTION>

    NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
<S>                                        <C>                                   <C>

Crow, Steve                                                   10,770                10,770
Crum, Stacey                                                   2,154                 2,154
Davis, Judy                                                   10,770                10,770
Dhawan, Vishal                                               127,896               127,896
Digby, Amy                                                     2,692                 2,692
D'Souza, Marcius                                               5,744                 5,744
Embuscado, Arnel                                               3,590                 3,590
Ford, Eugene (Dan)                                             4,308                 4,308
Fredericks, Steve                                              1,795                 1,795
Godfrey, Charles                                               4,308                 4,308
Godfrey, Hedyeh                                                4,308                 4,308
Gray, Josh                                                    19,745                19,745
Green, David                                                   1,076                 1,076
Hamilton, John                                                 1,436                 1,436
Hanson, Bruce                                                 12,026                12,026
Herring, Becky                                                 1,256                 1,256
Hibbard, Mike                                                  9,872                 9,872
Higgins, Jacqui                                                2,154                 2,154
Hodges, Steve                                                  1,257                 1,257
Hoehl, Karen                                                   4,308                 4,308
Hyde, Sara                                                     1,346                 1,346
Jacobs, Sarah                                                 10,770                10,770
Jian, David                                                    1,795                 1,795
Kang, Michael                                                  1,795                 1,795
Kulesa, Susan                                                  4,667                 4,667
Kumpf, Tom                                                     9,155                 9,155
Langhorne, Darren                                             11,488                11,488
Larison, Beverly                                               1,257                 1,257
Larson, Jinann                                                 1,257                 1,257
Lenhard, Chris                                                 1,077                 1,077
Lindsey, Lynn                                                  1,077                 1,077
Logan, Paul                                                   43,080                43,080
Mentall, David                                                 1,256                 1,256
Meredith, Susan                                                1,795                 1,795
Michael, Karina                                                8,975                 8,975
Michallas, George                                              8,616                 8,616
Moore, Dan                                                   185,337               185,337
Patterson, James                                               4,308                 4,308
Pinheiro, Karen                                                1,256                 1,256
Rao, Kanchana                                                  1,436                 1,436
Ratay, Bob                                                     1,616                 1,616
Riegle, Jill                                                   8,975                 8,975
Rodgers, Tad                                                  52,504                52,504
Saeger, Terry                                                 17,770                17,770
Sage, Laurie                                                   2,512                 2,512
Sahoo, J Ramesh                                                2,692                 2,692
Schlimmee, Kurt                                               28,002                28,002
Shields, Bob                                                   1,256                 1,256
Shomo, Milton                                                 10,052                10,052
Siegler, Ben                                                   6,102                 6,102
Sillah, Bintou                                                 1,076                 1,076
Sokol, Nellie                                                 10,770                10,770
</TABLE>



<PAGE>

<TABLE>
<CAPTION>

    NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
<S>                                        <C>                                   <C>

Stathopolous, George                                           2,154                 2,154
Sussman, Chris                                                 2,154                 2,154
Thompson, Aaron                                               26,207                26,207
Upadhyaya, Vasudha                                             1,795                 1,795
Watson, Joe                                                    7,180                 7,180
Weiss, Keith                                                  35,900                35,900
Whetzel, Jean                                                  1,975                 1,975
Whittle, Mark                                                 23,334                23,334
Wilkins, Jeff                                                 15,796                15,796
Williams, Charla                                               8,616                 8,616
Wilson, Tim                                                    2,872                 2,872
Wooding, Michele                                               4,128                 4,128
Wright, Kathy                                                 27,284                27,284
Zalubas, Mark                                                  8,975                 8,975
Zhu, Ziaoquing                                                 2,154                 2,154
Other non-affiliates of iBasis                                41,840                41,840

         TOTAL                                               987,262               987,262
         =====                                               =======               =======
</TABLE>

(1)      Beneficial ownership is determined in accordance with Rule 13d-3(d)
         promulgated by the SEC under the Securities and Exchange Act of 1934,
         as amended.


                              PLAN OF DISTRIBUTION

         The shares offered hereby by the selling stockholders may be sold
from time to time by the selling stockholders as a principal or through one
or more brokers, dealers or agents from time to time in one or more
transactions, which may involve crosses or block transactions, in special
offerings, in negotiated transactions, or otherwise. Any of these
transactions may be effected at market prices prevailing at the time of sale,
at prices related to prevailing market prices, at varying prices determined
at the time of sale or at negotiated or fixed prices, in each case as
determined by the selling stockholders or by agreement between the selling
stockholders and brokers, dealers or agents, or purchasers. The selling
stockholders may effect transactions by selling the shares directly to
purchasers or by selling shares to or through brokers or dealers and these
brokers or dealers may receive compensation in the form of discounts,
concessions or commissions from the selling stockholders or the purchasers of
the shares for whom these brokers or dealers may act as agent, or to whom
they sell as principal, or both, which compensation to a particular broker or
dealer might be in excess of customary commissions or be changed from time to
time. The selling stockholders and any brokers, dealers or agents who
participate in a sale of the shares may be deemed "underwriters" within the
meaning of Section 2(11) of the Securities Act of 1933 and the commissions
paid or discounts allowed to any of these brokers, dealers or agents in
addition to any profits received on resale of the shares if any of these
brokers, dealers or agents should purchase any shares as a principal may be
deemed to be underwriting discounts or commissions under the Securities Act
of 1933.

         In addition, any shares covered by this prospectus that qualify for
sale pursuant to Rules 701 and 144 of the Securities Act may be sold under Rules
701 and 144 rather than pursuant to the prospectus. A selling stockholder also
may pledge the shares as collateral for margin accounts and the shares may be
resold pursuant to the terms of these accounts.

         We will pay all of the expenses incident to the registration of the
shares to the public hereunder other than commissions, fees and discounts of
brokers, dealers, agents and the selling stockholders' attorney's fees.


                                 USE OF PROCEEDS

         We will not receive any of the proceeds from the sale of any of the
shares by the selling stockholders.


<PAGE>

                                LEGAL PROCEEDINGS

         Beginning August 1, 2001, we were served with several class action
complaints that were filed in the United States District Court for the Southern
District of New York against us and several of our officers, directors, and
former officers and directors, as well as against the investment banking firms
that underwrote our November 11, 1999 initial public offering of common stock.
The complaints were filed on behalf of persons who purchased our common stock
during different time periods, all beginning on or after November 10, 1999 and
ending on or before December 6, 2000. The complaints are similar to each other
and to hundreds of other complaints filed recently against other issuers and
their underwriters, and allege violations of the Securities Act of 1933 and the
Securities Exchange Act of 1934 primarily based on the assertion that there was
undisclosed compensation received by our underwriters in connection with our
initial public offering.

         Although neither iBasis nor the individual defendants have filed
answers in any of these matters, iBasis believes that it and the individual
defendants have meritorious defenses to the claims made in the complaints and
intends to contest the lawsuits vigorously. However, there can be no assurance
that we will be successful in such a defense. In addition, even though we have
insurance and contractual protections that could cover some or all of the
potential damages in these cases, or amounts that we might have to pay in
settlement of these cases, an adverse resolution of one or more of these
lawsuits could have a material adverse affect on our financial position and
results of operation in the period in which the lawsuits are resolved. Given the
early stage of the proceedings, we are not presently able to estimate potential
losses, if any, related to the lawsuits.


                                     EXPERTS

         The financial statements of iBasis, Inc. incorporated by reference
in this prospectus and elsewhere in the Registration Statement, have been
audited by Arthur Andersen LLP, independent public accountants, as indicated
in their report with respect thereto, and are incorporated by reference
herein in reliance upon the authority of said firm as experts in giving said
reports.

         The financial statements of PriceInteractive, Inc. incorporated by
reference in this prospectus and elsewhere in the Registration Statement have
been audited by Arthur Andersen LLP, independent public accountants, as
indicated in their report with respect thereto, and are included herein in
reliance upon the authority of said firm as experts in giving said reports.

<PAGE>


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3:  INCORPORATION OF DOCUMENTS BY REFERENCE

         We incorporate by reference the following documents filed by us with
the Securities and Exchange Commission:

<TABLE>
<CAPTION>

                                                                                      PERIOD OR DATE
<S>                                                                                <C>

The description of our common stock contained in our registration statement
filed with the SEC under Section 12(g) of the Securities Exchange Act, including
any amendment or report filed for the purpose of updating such description .....      Filed August 24, 1999


Annual Report on Form 10-K......................................................      Filed February 26, 2001


Current Report on Form 8-K......................................................      Filed March 14, 2001


Quarterly Report on Form 10-Q...................................................      Filed August 14, 2001
</TABLE>


         In addition, all documents subsequently filed by us pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of
a post-effective amendment which indicates that all securities offered hereby
have been sold or which deregisters all of such securities then remaining
unsold, shall be deemed to be incorporated by reference into this Registration
Statement and to be a part hereof from the date of filing of such documents.

ITEM 4:  DESCRIPTION OF SECURITIES

         Not applicable.

ITEM 5:  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not applicable.

ITEM 6:  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation Law empowers a Delaware
corporation to indemnify its officers and directors and specified other persons
to the extent and under the circumstances set forth therein.

         The Amended and Restated Certificate of Incorporation and the Amended
and Restated By-Laws of the Company, copies of which have been filed as Exhibits
3.1 and 3.2 to iBasis' Annual Report on Form 10-K for its fiscal year ended
December 31, 2000, provide for advancement of expenses and indemnification of
officers and directors of iBasis and specified other persons against liabilities
and expenses incurred by any of them in certain stated proceedings and under
certain stated conditions to the fullest extent permissible under Delaware law.

         We intend to maintain insurance for the benefit of our directors and
officers insuring these persons against certain liabilities, including
liabilities under the securities laws.


<PAGE>

ITEM 7:  EXEMPTION FROM REGISTRATION CLAIMED.

         The issuance of the shares of restricted stock covered by this
Registration Statement and offered for resale by the prospectus included herein
were made in reliance on, among other applicable exemptions from registration,
Rule 701 of the Securities Act.

ITEM 8:  EXHIBITS

         The following exhibits are filed as part of this Registration
Statement:

         4.1      Specimen Certificate for shares of the Registrant's common
                  stock (incorporated by reference from Exhibit Specimen
                  Certificate for shares of the Registrant's common stock to the
                  Registrant's Registration Statement on Form S-1 (file no.
                  333-85545)).

         4.2      The PriceInteractive Amended and Restated 2000 Restricted
                  Stock Plan.

         4.3      Form of Award Agreement issued under the PriceInteractive
                  Amended and Restated 2000 Restricted Stock Plan.

         5        Opinion of Bingham Dana LLP, counsel to the Registrant,
                  regarding the legality of the shares of common stock
                  registered hereunder.

         23.1     Consent of Arthur Andersen LLP.

         23.2     Consent of Arthur Andersen LLP.

         23.3     Consent of Bingham Dana LLP, counsel to the Registrant
                  (included in Exhibit 5).

         24       Power of Attorney (contained on the signature page of this
                  Registration Statement).

------------------------------


ITEM 9:  UNDERTAKINGS

         The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement to include any
material information with respect to the plan of distribution not previously
disclosed in the Registration Statement or any material change to such
information in the Registration Statement;

         (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
Registration Statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof;

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering;

         (4) That, for purposes of determining any liability under the
Securities Act of 1933, each filing of the Registrant's annual report pursuant
to Section 13(a) or 15(d) of the Exchange Act that is incorporated by reference
in the Registration Statement shall be deemed to be a new Registration Statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and

         (5) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.


<PAGE>


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in Burlington, Massachusetts on the 17th day of August, 2001.

                                     iBASIS, INC


                                     By:  /s/ OFER GNEEZY
                                          -------------------------------------
                                          Ofer Gneezy
                                          President and Chief Executive Officer

                                POWER OF ATTORNEY

         We, the undersigned officers and Directors of iBasis, Inc., hereby
severally constitute and appoint Ofer Gneezy and Jonathan Draluck, and each of
them singly, our true and lawful attorneys with full power to them, and each of
them singly, to sign for us and in our names in the capacities indicated below
the Registration Statement on Form S-8 filed herewith and any and all
pre-effective and post-effective amendments to said Registration Statement, and
generally to do all such things in our names and on our behalf in our capacities
as officers and Directors to enable iBasis to comply with the provisions of the
Securities Act, and all requirements of the Securities and Exchange Commission,
hereby ratifying and confirming our signatures, as they may be signed by our
said attorneys or any of them, to said Registration Statement and any and all
amendments thereto.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated.

<TABLE>
<CAPTION>

    SIGNATURE                                                          TITLE                           DATE
<S>                                                   <C>                                          <C>


                                                      President, Chief Executive Officer
/s/ OFER GNEEZY                                       and Director (Principal Executive
------------------------------------                  Officer)
    Ofer Gneezy


                                                      Vice President, Corporate
                                                      Development, Interim Chief Financial
/s/ D.J. LONG                                         Officer (Principal Financial and
------------------------------------                  Accounting Officer)
    D.J. Long


/s/ GORDON J.  VANDERBRUG                             Executive Vice President and Director
------------------------------------
    Gordon J.  VanderBrug


/s/ DANIEL PRICE                                      Director
------------------------------------
    Daniel Price


/s/ CHARLES N.  CORFIELD                              Director
------------------------------------
    Charles N.  Corfield


/s/ CHARLES M.  SKIBO                                 Director
------------------------------------
    Charles M. Skibo


/s/ CARL REDFIELD                                     Director
-------------------------------------
    Carl Redfield


/s/ W. FRANK KING                                     Director
--------------------------
    W. Frank King
</TABLE>


<PAGE>


                                  EXHIBIT INDEX

  EXHIBIT NO                 DESCRIPTION OF DOCUMENTS
  ----------                 ------------------------

         4.1      Specimen Certificate for shares of the Registrant's common
                  stock (incorporated by reference from Exhibit Specimen
                  Certificate for shares of the Registrant's common stock to the
                  Registrant's Registration Statement on Form S-1 (file no.
                  333-85545)).

         4.2      The PriceInteractive Amended and Restated 2000 Restricted
                  Stock Plan.

         4.3      Form of Award Agreement issued under the PriceInteractive
                  Amended and Restated 2000 Restricted Stock Plan.

         5        Opinion of Bingham Dana LLP, counsel to the Registrant,
                  regarding the legality of the shares of common stock
                  registered hereunder.

         23.1     Consent of Arthur Andersen LLP.

         23.2     Consent of Arthur Andersen LLP.

         23.3     Consent of Bingham Dana LLP, counsel to the Registrant
                  (included in Exhibit 5).

         24       Power of Attorney (contained on the signature page of this
                  Registration Statement).

---------------------------
[{"type": "S-8", "sequence": "1", "filename": "a2057356zs-8.txt", "description": "FORM S-8", "secsgml_size_bytes": 90205}]
{"company-data": {"conformed-name": "IBASIS INC", "cik": "0001091756", "assigned-sic": "7389", "irs-number": "043332534", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-67780", "film-number": "1717735"}, "business-address": {"street1": "20 SECOND AVE", "city": "BURLINGTON", "state": "MA", "zip": "01803", "phone": "7815057500"}, "mail-address": {"street1": "20 SECOND AVE", "city": "BURLINGTON", "state": "MA", "zip": "01803"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 17, 2001
                                                             FILE NO. 333-______

===============================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                          ----------------------------

                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                          ----------------------------

                                  IBASIS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

           DELAWARE                                            04-3332534
(STATE OR OTHER JURISDICTION OF                             (I.R.S. EMPLOYER
 INCORPORATION OR ORGANIZATION)                            IDENTIFICATION NO.)

                     20 SECOND AVENUE, BURLINGTON, MA 01803
               (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES) (ZIP CODE)

                          ----------------------------

     SHARES OF RESTRICTED STOCK ORIGINALLY ISSUED OR TO BE ISSUED UNDER THE

     PRICEINTERACTIVE, INC. AMENDED AND RESTATED 2000 RESTRICTED STOCK PLAN

           ASSUMED BY IBASIS, INC. IN CONNECTION WITH THE ACQUISITION
                            OF PRICEINTERACTIVE, INC.

                            (FULL TITLE OF THE PLAN)

                          ----------------------------

                                   OFER GNEEZY
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                  iBasis, Inc.
                                20 Second Avenue
                              Burlington, MA 01803
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (781) 505-7500
           TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE

                          ----------------------------

                                   COPIES TO:

                             JOHAN V. BRIGHAM, ESQ.
                                BINGHAM DANA LLP
                               150 Federal Street
                              Boston, MA 02110-1726
                                 (617) 951-8000

                         CALCULATION OF REGISTRATION FEE
================================================================================================================================
                 TITLE OF                 AMOUNT TO BE      PROPOSED MAXIMUM            PROPOSED MAXIMUM           AMOUNT OF
        SECURITIES TO BE REGISTERED        REGISTERED    OFFERING PRICE PER SHARE    AGGREGATE OFFERING PRICE   REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
Common Stock,  $0.01 par value per
   share...............................     987,262            $1.95 (1)               $1,925,160.90 (1)           $482.00
--------------------------------------------------------------------------------------------------------------------------------
(1)      Estimated solely for the purpose of determining the registration fee.
         Calculated in accordance with Rule 457(c), based on the offering of up
         to 987,262 shares at a purchase price of $1.95 per share, which is the
         average of high and low prices reported on the Nasdaq National Market
         quotation system on August 10, 2001. It is not known how many of these
         shares will be sold under this Registration Statement or at what price
         these shares will be sold.

===============================================================================
P R O S P E C T U S

                                 987,262 SHARES
                                  IBASIS, INC.

                                  COMMON STOCK

         Selling stockholders identified or described in this prospectus may
sell up to 987,262 shares of common stock of iBasis, Inc. iBasis will not
receive any of the proceeds from the sale of shares by the selling stockholders.
iBasis' common stock is listed on the Nasdaq National Market quotation system
under the symbol "IBAS". On August 10, 2001, the closing price of the common
stock, as reported on Nasdaq, was $1.90 per share.

         THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS
THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.

         The selling stockholders may sell the shares of common stock described
in this prospectus in public or private transactions at prevailing market
prices, or at privately negotiated prices. The selling stockholders may sell
shares directly to purchasers or through brokers or dealers. Brokers or dealers
may receive compensation in the form of discounts, concessions or commissions
from the selling stockholders. More information is provided in the section
titled "Plan of Distribution."

                 The date of this prospectus is August 17, 2001.
WHERE YOU CAN GET MORE INFORMATION

         You should rely only on the information contained in this document or
to which we have referred you. We have not authorized anyone to provide you with
information that is different. This prospectus is not an offer to sell, or a
solicitation of an offer to buy, any securities other than the shares of common
stock to which it relates, or an offer of these shares of common stock to any
person in any jurisdiction in which such offer is unlawful. The information
contained in this document may only be accurate as of the date of this document.

         This prospectus constitutes part of a registration statement filed by
iBasis with the Securities and Exchange Commission under the Securities Act of
1933. This prospectus does not contain all of the information set forth in the
registration statement, since we have omitted some parts in accordance with the
SEC's rules and regulations. For further information about iBasis and the shares
being offered by this prospectus, please refer to the registration statement and
to its exhibits. Copies of the registration statement may be inspected, without
charge, at the offices of the SEC, or obtained at prescribed rates from the
public reference facilities of the SEC at the address set forth below.

         iBasis files annual, quarterly and special reports, proxy statements
and other information with the SEC pursuant to the information requirements of
the Securities Exchange Act of 1934. You may read and copy any document filed by
us at the public reference facilities of the SEC located at 450 Fifth Street
N.W., Washington, D.C. 20549. You may obtain information on the operation of the
SEC's public reference facilities by calling the SEC at 1-800-SEC-0330. You can
also access copies of this material electronically on the SEC's home page on the
Web at http://www.sec.gov. iBasis' common stock is traded on the Nasdaq National
Market System, and information concerning us is also available for inspection at
the offices of the Nasdaq National Market, Reports Section, 1735 K Street, N.W.,
Washington, DC 20006.

         The SEC permits us to "incorporate by reference" the information that
we file with them, which means that we can disclose important information to you
by referring you to those documents. We incorporate by reference the documents
listed below and any future filings we will make with the SEC under Section
13(a), 13(c), 14 or 15(d) of the Securities Exchange Act prior to the filing of
a post-effective amendment that indicates that all securities offered by our
registration statement have been sold or that deregisters all of our securities
then remaining unsold:

1.       our annual report on Form 10-K filed on February 26, 2001 for the year
         ended December 31, 2000;

2.       our current report on Form 8-K filed on March 14, 2001;

3.       our quarterly report on Form 10-Q filed on August 14, 2001; and

4.       the description of our common stock contained in our registration
         statement filed with the SEC on August 24, 1999 under Section 12(g) of
         the Securities Exchange Act, including any amendment or report filed
         for the purpose of updating such description.

         Any statement in the documents incorporated by reference in this
prospectus shall be deemed to be modified or superseded for purposes of this
prospectus to the extent that a statement contained in this prospectus modifies
or supersedes the statement. Any statement that is so modified or superseded
shall not be deemed, except as modified or superseded, to constitute a part of
this prospectus.

         You may obtain without charge, upon written or oral request, a copy of
(1) any of the documents incorporated by reference in this prospectus, but not
exhibits to these documents, and (2) copies of all reports, proxy statements and
other communications distributed by iBasis to its security holders generally,
but not to the extent you have already received these reports, proxy statements
and other communications. You should address requests to iBasis, Inc.,
Attention: Investor Relations, 20 Second Avenue, Burlington, Massachusetts
01803, (781) 505-7500.
FORWARD-LOOKING STATEMENTS

         This prospectus contains "forward-looking statements" within the
meaning of Section 27A of the Securities Act and Section 21E of the Exchange
Act. We intend the forward-looking statements to be covered by the safe harbor
for forward-looking statements in these sections. These forward-looking
statements include, without limitation, statements about our market opportunity,
strategies, competition, expected activities, expected profitability and
investments as we pursue our business plan, and the adequacy of our available
cash resources. These forward-looking statements are usually accompanied by
words such as "believe," "anticipate," "plan," "seek," "expect," "intend" and
similar expressions. The forward-looking information is based on various factors
and was derived using numerous assumptions.

         Forward-looking statements necessarily involve risks and
uncertainties, and our actual results could differ materially from those
anticipated in the forward-looking statements due to a number of factors,
including those set forth below under "Risk Factors" and elsewhere in this
prospectus and in the information incorporated by reference herein. The
factors set forth below under "Risk Factors" and other cautionary statements
made in or incorporated by reference into this prospectus should be read and
understood as being applicable to all related forward-looking statements
wherever they appear in this prospectus. The forward-looking statements
contained in this prospectus represent our judgment as of the date of this
prospectus. iBasis cautions readers not to place undue reliance on these
statements. We undertake no obligation to update publicly any forward-looking
statements for any reason, even if new information becomes available or other
events occur in the future.

                                  RISK FACTORS

         ANY INVESTMENT IN OUR SHARES OF COMMON STOCK INVOLVES A HIGH DEGREE
OF RISK. YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED BELOW, WHICH WE
BELIEVE ARE ALL THE MATERIAL RISKS TO OUR BUSINESS, INCLUDING THE BUSINESS OF
PRICEINTERACTIVE, INC. OF RESTON, VIRGINIA, WHICH WE ACQUIRED FEBRUARY 27,
2001 AND WHICH IS NOW CALLED OUR SPEECH SOLUTIONS LINE OF BUSINESS, TOGETHER
WITH THE INFORMATION CONTAINED ELSEWHERE IN OR INCORPORATED BY REFERENCE INTO
THE PROSPECTUS, BEFORE YOU MAKE A DECISION TO INVEST IN OUR COMPANY.

                         RISKS RELATED TO OUR OPERATIONS

WE HAVE A LIMITED OPERATING HISTORY UPON WHICH TO BASE YOUR INVESTMENT DECISION,
AND YOU MAY INACCURATELY ASSESS OUR PROSPECTS FOR SUCCESS.

We were incorporated in August 1996 and first began to offer commercial services
in May 1997. Due to our limited operating history, it is difficult for us to
predict future results of operations both for our core business and our enhanced
service offerings. Moreover, we cannot be sure that we have accurately
identified all of the risks to our business, especially because we use new, and
in many cases, unproven technologies and provide new services, the technical
implementation of which on a commercial scale, and widespread commercial
acceptance of, is yet unproven. As a result, our past results and rates of
growth may not be meaningful indicators of our future results of operations.
Also, your assessment of the prospects for our success may prove inaccurate.

WE HAVE A HISTORY OF OPERATING LOSSES AND MAY NEVER BECOME PROFITABLE.

During 2000, we incurred a net loss of $62.3 million. As of June 30, 2001, we
had an accumulated deficit of $210 million. We expect to continue to incur
operating losses and negative cash flows as we incur significant operating
expenses and make capital investments in our business. Our future profitability
will depend on our being able to deliver calls over our network at a cost to us
that is less than what we are able to charge for our calls, and utilize our
network to deliver new, enhanced services on a profitable basis. Our costs to
deliver calls are dependent on a number of factors, including the countries to
which we direct calls and whether we are able to use the Internet, rather than
another component of our network or more expensive back-up networks, to deliver
calls. The prices that we are able to charge to deliver calls over our network
vary, based primarily on the prices currently prevailing in the international
long distance carrier market to specific countries. While we are currently able
to terminate a substantial number of the calls carried over our network
profitably on an operating basis, we have been unable to
operate our entire network profitably on an operating basis for sustained
periods of time. Our ability to deliver new services or capabilities like
unified communications, our Speech Solutions offerings and other new services,
also depends on a variety of factors. Unified messaging, for which we use the
brand name VoCore(TM), allows our customers to offer end-users voicemail, email,
and faxes accessible from a variety of devices, including telephones and
personal computers. We have only begun to recognize revenue from VoCore as of
May, 2001. Our SpeechPort service offering has achieved only relatively small
amounts of revenue to date. It may take longer than we expect to gain acceptance
by customers for these services or for providing these services through our
network. In addition, we may be unable to make effective use of the technology
we employ, scale the service for wide use, or leverage our network
infrastructure adequately to take advantage of possible economies of scale. We
may not ever generate sufficient revenues, or reduce costs to the extent
necessary, to permit us to achieve profitability. Even if we do become
profitable, we may not sustain or increase profitability on a quarterly or
annual basis in the future.

FLUCTUATIONS IN OUR QUARTERLY RESULTS OF OPERATIONS THAT RESULT FROM VARIOUS
FACTORS INHERENT IN OUR BUSINESS MAY CAUSE THE MARKET PRICE OF OUR COMMON STOCK
TO FALL.

Our revenue and results of operations have fluctuated and may continue to
fluctuate significantly from quarter to quarter in the future due to a number of
factors, many of which are not in our control, including, among others:

o        the amount of Internet Telephony traffic we are able to sell to our
         customers, and their decisions on whether to route traffic over our
         network;

o        our ability to generate revenues from the delivery of enhanced services
         like VoCore, the Speech Solutions offerings or new services, that are
         appealing to the market;

o        pricing pressure in the international long distance market;

o        the percentage of traffic that we are able to carry over the Internet,
         or over our dedicated international private circuit lines, rather than
         over the more costly traditional public-switched telephone network;

o        loss of arbitrage opportunities resulting from declines in
         international settlement rates or tariffs;

o        our ability to negotiate lower termination fees charged by our local
         providers if our pricing deteriorates;

o        our continuing ability to negotiate competitive costs to interconnect
         our network with those of other carriers;

o        capital expenditures required to expand or upgrade our network;

o        changes in call volume among the countries to which we complete calls;

o        the portion of our total traffic that we carry over more attractive
         routes could fall, independent of route-specific price, cost or volume
         changes;

o        technical difficulties or failures of our network systems or
         third-party delays in expansion or provisioning system problems;

o        loss of major customers because of bankruptcies, or our inability to
         collect amounts owed to us; and

o        currency fluctuations in countries where we operate.

Because of these factors, you should not rely on quarter-to-quarter comparisons
of our results of operations as an indication of our future performance. It is
possible that, in future periods, our results of operations will be
significantly lower than the estimates of public market analysts and investors.
A discrepancy of this nature could cause the price of our common stock to
decline significantly.

WE MAY NEVER GENERATE SUFFICIENT REVENUE TO ATTAIN PROFITABILITY IF
COMMUNICATIONS SERVICE PROVIDERS AND OTHERS ARE RELUCTANT TO USE OUR SERVICES OR
DO NOT USE OUR SERVICES, INCLUDING ANY ENHANCED SERVICES, IN SUFFICIENT VOLUME.

If the market for Internet telephony and other new services does not develop as
we expect, or develops more slowly than expected, our business, financial
condition and results of operations will be materially and adversely affected.
Our customers may be reluctant to use our Internet telephony services for a
number of reasons, including:

o        perceptions that the quality of voice transmitted over the Internet is
         low;

o        perceptions that Internet telephony is unreliable;

o        our inability to deliver traffic over the Internet with significant
         cost advantages; and

o        development of their own capacity on routes served by us.
Our potential customers for our new services may be reluctant to use these
services as a result of perceptions that our enhanced services are unnecessary,
too expensive, ineffective, or not appealing to their end-users or client base.
The growth of our core business depends on carriers and other communications
service providers generating an increased volume of international voice and fax
traffic and selecting our network to carry at least some of this traffic. If the
volume of international voice and fax traffic fails to increase, or decreases,
and these third-parties do not employ our network, our ability to become
profitable will be materially and adversely affected. In addition, we cannot
assure investors that communications service providers and their end-users and
others will be receptive to, and subscribe to, unified communications services,
or any other enhanced services that we elect to deploy on our network. Any
perceived problems with the reliability or functionality of any new services
that we offer could discourage communications service providers or others from
offering these services to their customers. In addition, the development of new
capabilities, such as VoCore and other new services, may require substantial
additional capital expenditures to be made well in advance of generating any
revenue from these services or demonstrating any market acceptance of these
services. If carriers and other communications service providers do not employ
our network to offer any new services to their customers, or if their customers
do not subscribe for the services when offered, our results of operations will
be materially adversely affected. We cannot assure you that end-users will
continue to purchase services from our customers or that our customers will
maintain a demand for our services.

WE MAY NOT BE ABLE TO SUCCESSFULLY INTEGRATE THE SPEECH SOLUTIONS OPERATIONS AND
BUSINESS TO MAXIMIZE THE POTENTIAL BENEFITS OF THE MERGER.

After the merger with PriceInteractive,Inc., we have tried to preserve and
increase the potential benefits that may result from the combined companies.
These benefits include, among others, expanded and complementary product
offerings, an increased sales force, greater market exposure, and new technology
and engineering and development personnel. Achieving these benefits from the
merger will depend in part on the integration of our technology, operations and
personnel in a timely and efficient manner so as to minimize the risk that the
merger will result in the loss of market opportunity or key employees or the
diversion of the attention of management.

Among some of the challenges we continue to face are:

o        operational or technological procedures that may not be compatible;

o        significant diversion of management's time and attention that could
         otherwise be spent on attracting business prospects, enhancing services
         or other matters;

o        developing long-term strategies in dynamic business cultures and
         different markets;

o        maintaining key personnel without which it could be difficult to
         complete existing projects or undertake new projects; and

o        increased costs associated with the integration of the two companies.

In addition, we cannot assure you that our businesses will achieve revenues,
specific net income or loss levels, efficiencies or synergies that justify the
merger or that the merger will result in increased earnings for the combined
company in any future period. Further, the combined company may experience
slower rates of growth as compared to historical rates of growth of them
independently.

WE MAY FACE QUALITY AND CAPACITY PROBLEMS UPON FAILURES BY THIRD PARTIES.

VENDORS. Our Internet Telephony line of business relies upon third-party vendors
to provide us with the equipment and software that we use to transfer and
translate calls from traditional voice networks to the Internet, and vice versa.
For example, we purchase substantially all of our Internet telephony equipment
from Cisco Systems. Our Speech Solutions and messaging lines of business rely
upon third-party vendors to provide speech recognition and other technologies.
We cannot assure you that we will be able to continue purchasing this equipment
and software from our vendors on acceptable terms, if at all. If we become
unable to purchase from these vendors the software and equipment that we
require, we may not be able to maintain or expand our offerings to accommodate
growth. As a result, we may be unable to increase revenues sufficiently to
become profitable. See also "Strategic Relationships" below.
PARTIES THAT MAINTAIN PHONE AND DATA LINES. Our business model depends on the
availability of the Internet and traditional telephone networks to transmit
voice and fax calls, dial-up access to such networks, and to provide other
enhanced services. Third parties maintain and, in many cases, own these networks
and other components that comprise the Internet. Some of these third parties are
national telephone companies. They may increase their charges for using these
lines at any time and decrease our profitability. They may also fail to maintain
their lines properly and disrupt our ability to provide service to our
customers. Sometimes local governments may suspend or interrupt the access of
these lines. Any failure by these third parties to maintain these lines and
networks that leads to a material disruption of our ability to complete calls or
provide other services could discourage our customers from using our network or
enhanced services, which could have the effect of delaying or preventing our
ability to become profitable.

LOCAL COMMUNICATIONS SERVICE PROVIDERS. We maintain relationships with local
communications service providers in many countries for our Internet Telephony
business, some of whom own the equipment that translates voice to data in that
country. We rely upon these third parties both to provide lines over which we
complete calls and to increase their capacity when necessary as the volume of
our traffic increases. There is a risk that these third parties may be slow, or
fail, to provide capacity, which would affect our ability to complete calls to
those destinations. We cannot assure you that we will be able to continue our
relationships with these local service providers on acceptable terms, if at all.
Because we rely upon entering into relationships with local service providers to
expand into additional countries, we cannot assure you that we will be able to
increase the number of countries to which we provide service. We also may not be
able to enter into relationships with enough overseas local service providers to
handle increases in the volume of calls that we receive from our customers.
Finally, any technical difficulties that these providers suffer would affect our
ability to transmit calls to the countries that those providers help us serve.

STRATEGIC RELATIONSHIPS. We depend in part on our strategic relationships to
expand our distribution channels and develop and market our services. In
particular, we depend in large part on our joint marketing and product
development efforts with Cisco Systems to achieve market acceptance and brand
recognition in some markets. Our VoCore service relies on technology and
services from companies such as OpenWave, EMC and Hewlett-Packard. Strategic
relationship partners may choose not to renew existing arrangements on
commercially acceptable terms, if at all. In addition, our Speech Solutions
line of business also depends in part on its strategic relationships with
SpeechWorks International, Inc. and MicroStrategy. In general, if we lose
these or other key strategic relationships, or if we fail to maintain or
develop new relationships in the future, our ability to expand the scope and
capacity of our network and services provided, and to maintain
state-of-the-art technology, would be materially adversely affected. New
services will also rely on key strategic relationships, which will be subject
to the same considerations.

THE MARKET DEMAND FOR VOCORE, SPEECH SOLUTIONS, AS WELL AS ANY NEW SERVICES MAY
NOT DEVELOP AS ANTICIPATED, WHICH WOULD SUBSTANTIALLY IMPEDE OUR ABILITY TO
GENERATE REVENUES.

Our future financial performance depends in part on growth in demand for
VoCore, Speechport speech recognition services and products, and other
services including conferencing. If the market for these services and
products does not develop or if we are unable to capture a significant
portion of that market, either directly or through our partners, our
results of operations will be adversely affected. The markets for unified
messaging and voice application services and products is relatively new and
evolving. The adoption of these services and products could be hindered by
the perceived cost, quality and reliability of these new technologies, as
well as the reluctance among businesses that have invested substantially in
legacy equipment that provide traditional email, voicemail and/or
touch-tone-based, interactive voice response and other systems. The continued
development of the market for our enhanced services and products will depend
upon the:

o        widespread adoption of voice-driven applications by businesses for use
         in conducting transactions and managing relationships with their
         customers;

o        commitments by businesses and carriers of outsourced hosted solutions
         for messaging, call centers, and other applications such as
         conferencing;

o        widespread adoption of solutions to unify a variety of communications
         modes through one solution;
o        consumer acceptance of these applications; and

o        continuing improvements in hardware and software technology that may
         reduce the cost and improve the performance of voice solutions.

The market for speech-activated services is new and potential industry
standards, such as VoiceXML, have not yet matured. If multiple standards are
adopted, we may need to support them, which would require additional time and
resources, and could negatively impact revenue and margins. If we fail to meet
subscriber expectations, even if demand for VoCore and new voice application
services grows, the marketability of VoCore and any other service could be
materially reduced.

THE QUALITY OF SPEECH APPLICATIONS OVER AN IP NETWORK HAS NOT YET BEEN FULLY
PROVEN AND FAILURES BY VOICE SITE PROVIDERS TO ADOPT THESE APPLICATIONS MAY HARM
OUR FUTURE RESULTS OF OPERATIONS.

Speech applications, such as our SpeechPort, have not been extensively tested on
Internet Protocol infrastructures. If performance and accuracy of speech
services are negatively affected by a particular IP infrastructure, the
commercial acceptance of these applications by voice site providers on that
infrastructure will be low. Failure by voice site providers to adopt these
applications may have a material negative impact on our results of operations,
which could cause our stock price to decline. As an international company,
iBasis is also dependent upon the further development of text-to-speech and
speech recognition applications in multiple languages.

OUR CUSTOMERS MAY REQUIRE A LONGER SALES AND IMPLEMENTATION CYCLE OR COULD NOT
BE READY TO COMMIT TO OUTSOURCED SOLUTIONS, WHICH COULD NEGATIVELY AFFECT OUR
REVENUE PLANS.

If actual sales and development cycles for our enhanced offerings are
substantially longer than anticipated, revenue targets would not be met.
Additionally, revenue targets may not be met if businesses and our potential
customers delay their decisions to adoptand implement outsourced solutions for
speech-enabled applications. The failure or lack of effective third-party
technologies and services could limit our ability to generate revenues. Some of
our enhanced service offerings are dependent on technology developed by third
parties. These technologies include:

o        email servers that process both email messages and voicemail messages;

o        software that converts text to speech;

o        speech recognition software;

o        billing system software;

o        conferencing software; and

o        network operations center servers, routers and other equipment.

We will continue to incorporate third-party technologies in future unified
communications and speech application services and products. We have limited
control over whether or when these third-party technologies will be enhanced. In
addition, our competitors may acquire interests in these third parties or their
technologies, which may render the technology unavailable to us. If a third
party fails or refuses to timely develop, license or support technology
necessary to our services or products, market acceptance of our services or
products could be adversely affected. Moreover, if these third-party
technologies fail or otherwise prove to be not viable, it may have a significant
impact on our ability to provide our services and/or to generate revenues. In
addition, we rely and will continue to rely on services supplied by third
parties such as telecommunications, Internet access and electrical power for
services hosted in our network operations center. If these third-party services
fail to meet industry standards for quality and reliability, market acceptance
of our services could be adversely affected.
WE MAY NOT BE ABLE TO SUCCEED IN THE INTENSELY COMPETITIVE MARKET FOR OUR
VARIOUS SERVICES.

The market for Internet voice, fax and other enhanced services is extremely
competitive and will likely become more competitive. Internet protocol and
Internet telephony service providers, such as GRIC Communications and ITXC
Corp., route traffic to destinations worldwide and compete directly with us.
Also, Internet telephony service providers, such as Net2Phone, that presently
focus on retail customers, may in the future enter our market and compete with
us. These retail-oriented carriers also provide PC-to-PC services at very low
prices or for free. Perceived competition with this market segment could drive
our prices down. In addition, major telecommunications carriers, such as AT&T,
Deutsche Telekom, MCI WorldCom and Qwest Communications, have all entered or
announced plans to enter the Internet telephony market. In particular, AT&T
invested over $2 billion in Net2Phone in April. We also face competition from
other companies who offer unified communications and speech recognition
applications. We directly compete at the wholesale level with a number of other
unified communications providers such as deltathree.com, Orchestrate, Tornado
Development, and uReach. Some of the competition (e.g., deltathree.com and
Tornado Development) sell unified communications directly to end users in
addition to selling at the wholesale level. Furthermore, voice portal companies
such as TellMe and BeVocal may in the future develop business models that
compete directly with our Speech Solutions business. Many of these companies are
larger than we are and have substantially greater managerial and financial
resources than we do. Intense competition in our markets can be expected to
continue to impose downward pressure on prices and adversely affect our
profitability. We cannot assure you that we will be able to compete successfully
against our competitors and we may lose customers or fail to grow our business
as a result of this competition.

WE ARE SUBJECT TO DOWNWARD PRICING PRESSURES ON OUR WHOLESALE INTERNATIONAL
INTERNET TELEPHONY SERVICES AND A CONTINUING NEED TO RENEGOTIATE OVERSEAS RATES,
WHICH COULD DELAY OR PREVENT OUR PROFITABILITY.

As a result of numerous factors, including increased competition and global
deregulation of telecommunications services, prices for international long
distance calls have been decreasing. This downward trend of prices to end users
has caused us to lower the prices we charge communications service providers for
call completion on our network. If this downward pricing pressure continues, we
cannot assure you that we will be able to offer Internet telephony services at
costs lower than, or competitive with, the traditional voice network services
with which we compete. Moreover, in order for us to lower our prices, we have to
renegotiate rates with our overseas local service providers who complete calls
for us. We may not be able to renegotiate these terms favorably enough, or fast
enough, to allow us to continue to offer services in a particular country on a
cost-effective basis. The continued downward pressure on prices and our failure
to renegotiate favorable terms in a particular country would have a material
adverse effect on our ability to operate our network and Internet telephony
business profitably.

A VARIETY OF RISKS ASSOCIATED WITH OUR INTERNATIONAL OPERATIONS COULD MATERIALLY
ADVERSELY AFFECT OUR BUSINESS.

Because we provide many of our services internationally, we are subject to
additional risks related to operating in foreign countries. In particular, in
order to provide services and operate facilities in some countries, we have
established subsidiaries or other legal entities. Associated risks include:

o        unexpected changes in tariffs, trade barriers and regulatory
         requirements relating to Internet access or Internet telephony, or
         enhanced services;

o        economic weakness, including inflation, or political instability in
         particular foreign economies and markets;

o        difficulty in collecting accounts receivable;

o        compliance with tax, employment immigration and labor laws for
         employees living and traveling abroad;

o        foreign taxes including withholding of payroll taxes; and

o        foreign currency fluctuations, which could result in increased
         operating expenses and reduced revenues; and other obligations incident
         to doing business or operating a subsidiary in another country.

In addition, we are subject to a variety of risks associated with the provision
of unified communications and international voice site business management, any
of which could negatively affect our business. These risks include providing
easy telephone access to The iBasis Network(TM) and relying on third party
vendors to create and
refine different language models for each particular language or dialect.
These language models are required to create versions of our products that
allow end users to speak the local language or dialect and be understood and
authenticated. If vendors fail to develop localized versions of our products,
our ability to address international market opportunities and to grow our
business will be limited. These and other risks associated with our
international operations may materially adversely affect our ability to
attain or maintain profitable operations. A significant portion of our
revenue has historically been generated by delivering calls to Asian, Middle
Eastern and Latin American countries. Political or economic instability in
countries to which we deliver substantial volumes of traffic could lead to
difficulties in completing calls through our regional service providers or
decreased call volume to these countries.

IF WE ARE NOT ABLE TO KEEP UP WITH THE RAPID TECHNOLOGICAL CHANGE IN A
COST-EFFECTIVE WAY, THE RELATIVE QUALITY OF OUR SERVICES COULD SUFFER.

The technology upon which our services depend is changing rapidly. Significant
technological changes could render the hardware and software that we use
obsolete, and competitors may begin to offer new services that we are unable to
offer. We must adapt to our rapidly changing market by continually improving the
responsiveness, reliability, services and features of our network and by
developing new features and applications to meet customer needs. If we are
unable to respond successfully to these developments or do not respond in a
cost-effective way, we may not be able to offer competitive services.

WE MAY NOT BE ABLE TO EXPAND AND UPGRADE OUR NETWORK ADEQUATELY AND
COST-EFFECTIVELY TO ACCOMMODATE ANY FUTURE GROWTH.

Our Internet telephony business requires that we handle a large number of
international calls simultaneously. As we expand our operations, we expect to
handle significantly more calls as well as other services. We will need to
expand and upgrade our hardware and software to accommodate increased traffic.
If we do not expand and upgrade quickly enough, we will not have sufficient
capacity to handle the traffic and growth in our operating performance would
suffer. Even with this expansion, we may be unable to manage new deployments or
utilize them in a cost-effective manner. In addition to lost growth
opportunities, any one of these failures could adversely affect customer
confidence in The iBasis Network and could result in us losing business
outright.

IF THE INTERNET DOES NOT REMAIN VIABLE AND CONTINUE TO GROW AS A MEDIUM FOR
VOICE AND FAX COMMUNICATIONS AND OTHER ENHANCED SERVICES, OUR BUSINESS WILL
SUFFER.

The technology that allows voice and fax communications, and the delivery of
other enhanced services and capabilities like VoCore and our Speech Solutions
services, over the Internet, are still in the early stages of development.

Our future success will depend in part upon the maintenance of the Internet
infrastructure, including a reliable network backbone with the necessary speed,
data capacity and security for providing reliability and timely Internet access
and services. To the extent that the Internet continues to experience increased
numbers of users, frequency of use or bandwith requirements, the Internet may
become congested and be unable to support the demands placed on it and its
performance or reliability may decline thereby impairing our ability to complete
calls and provide other services using the Internet at consistently high
quality. As a result of the Internet's capacity constraints, callers could
experience delays, errors in transmissions or other interruptions in service.
Transmitting telephone calls over the Internet, and other uses of the Internet
for our enhanced services, must also be accepted by customers as an alternative
to traditional services. Moreover, critical issues concerning the commercial use
of the Internet, including security, cost, ease of use and access, intellectual
property ownership and other legal liability issues, remain unresolved and could
materially and adversely affect both the growth of Internet usage generally and
our business in particular.

Finally, if the overall performance of the Internet is seriously downgraded by
Website attacks or other acts of computer vandalism or virus infection, our
ability to deliver our communication services over the Internet could be
adversely impacted.
IF WE FAIL TO MANAGE OUR GROWTH, WE COULD LOSE CUSTOMERS.

We have grown rapidly and expect to continue to do so. In order to increase the
number of our customers and the size of our operations, we will need to improve
our administrative, accounting, operating systems and controls. We may need to
redesign several internal systems. Our attention to these matters may distract
us from other aspects of our business. Moreover, failure to implement new
systems and controls may hamper our ability to provide services to customers and
may impair the quality of our services, which could result in the loss of
customers.

OUR CASH RESERVES WOULD DECLINE SIGNIFICANTLY IF WE CANNOT COLLECT DEBTS FROM
OUR CUSTOMERS.

We generate much of our revenue from a limited number of customers. Customers
may also discontinue their use of our services at any time, and without notice.
Some of our customers have filed for bankruptcy or are in the midst of
reorganizing. Other customers have delayed payments to owed to us. We may be
unable to collect amounts due to us by these customers. Therefore, in any given
quarter, we would lose a significant amount of revenue or cash if we lost one or
more major customers or if a major customer is unable or unwilling to pay
amounts owed to us on a timely basis or at all.

WE DEPEND ON OUR KEY PERSONNEL AND MAY HAVE DIFFICULTY ATTRACTING AND RETAINING
THE SKILLED EMPLOYEES WE NEED TO EXECUTE OUR GROWTH PLANS. WE DEPEND HEAVILY ON
OUR KEY MANAGEMENT.

Our future success will depend, in large part, on the continued service of
our key management and technical personnel. If any of these individuals are
unable or unwilling to continue in their present positions, our business,
financial condition and results of operations would suffer. We do not carry
key person life insurance on our personnel. While most of our key management
has entered into employment agreements with us, these agreements do not
ensure their continued employment with us.

WE WILL NEED TO ATTRACT SKILLED PERSONNEL TO EXECUTE OUR GROWTH PLANS.

Our future success will depend, in large part, on our ability to attract, retain
and motivate highly skilled employees, particularly engineering and technical
personnel. Competition for these employees in our industry at times has been
intense. We have from time to time in the past experienced, and we expect to
continue to experience in the future, difficulty in hiring and retaining
employees with appropriate qualifications. We may not be able to retain our
employees or attract, assimilate or retain other highly qualified employees in
the future. If we do not succeed in attracting and retaining skilled personnel,
we may not be able to grow at a sufficient rate to achieve profitable
operations.

A FAILURE TO OBTAIN NECESSARY ADDITIONAL CAPITAL IN THE FUTURE ON ACCEPTABLE
TERMS COULD PREVENT US FROM EXECUTING OUR BUSINESS PLAN.

We may need additional capital or cash in the future to fund our operations,
finance investments in equipment and corporate infrastructure, expand our
network, increase the range of services we offer and respond to competitive
pressures and perceived opportunities. Cash flow from operations, and cash on
hand may not be sufficient to cover our operating expenses and capital
investment needs. We cannot assure you that additional financing will be
available on terms acceptable to us, if at all. We may pursue different
strategies of raising funds necessary to maintain or grow operations. These
strategies may include but are not limited to, bank or equipment financings,
and raising funds through equity sales or sales of assets, among other
strategies. A failure to obtain additional funding could prevent us from
making expenditures that are needed to allow us to grow or maintain our
operations. If we raise additional funds by selling equity securities, the
relative equity ownership of our existing investors could be diluted or the
new investors could obtain terms more favorable than previous investors. If
we raise additional funds through debt financing, we could incur significant
borrowing costs. The failure to obtain additional financing when required
could result in our being unable to grow as required to attain profitable
operations.
THE ANTICIPATED GAINS OF OUR INVESTMENTS IN CAPITAL INFRASTRUCTURE AND IN
STRATEGIC EQUITY ACQUISITIONS MAY NEVER BE REALIZED.

We have invested heavily in overseas operations and deployed Internet central
offices in various countries around the world. Due to our ability to exchange
telephony and data traffic with major customers at fewer points, we find it is
no longer necessary to deploy such infrastructure. We have also made equity
investments in strategic partners, which have failed or are not generating the
returns that were expected. These investments may have a negative impact on our
cash and financial position. We may never be able to realize a return on these
investments.

IF WE ARE UNABLE TO PROTECT OUR INTELLECTUAL PROPERTY, OUR COMPETITIVE POSITION
WOULD BE ADVERSELY AFFECTED.

We rely on patent, trademark and copyright law, trade secret protection and
confidentiality and/or license agreements with our employees, customers,
partners and others to protect our intellectual property. Unauthorized third
parties may copy our services or reverse engineer or obtain and use information
that we regard as proprietary. End-user license provisions protecting against
unauthorized use, copying, transfer and disclosure of any licensed program may
be unenforceable under the laws of certain jurisdictions and foreign countries.
We may seek to patent software or equipment in the future. We do not know if any
of our future patent applications will be issued with the scope of the claims we
seek, if at all. In addition, the laws of some foreign countries do not protect
proprietary rights to the same extent as do the laws of the United States. Our
means of protecting our proprietary rights in the United States or abroad may
not be adequate and third parties may infringe or misappropriate our copyrights,
trademarks and similar proprietary rights. If we fail to protect our
intellectual property and proprietary rights, our business, financial condition
and results of operations would suffer. We believe that we do not infringe upon
the proprietary rights of any third party, and no third party has asserted a
material patent infringement claim against us. It is possible, however, that
such a claim might be asserted successfully against us in the future. Our
ability to provide our services depends on our freedom to operate. That is, we
must ensure that we do not infringe upon the proprietary rights of others or
have licensed all necessary rights. We have not requested or obtained an opinion
from counsel as to whether our services infringe upon the intellectual property
rights of any third parties. A party making an infringement claim could secure a
substantial monetary award or obtain injunctive relief that could effectively
block our ability to provide services in the United States or abroad. We have
received letters and other notices claiming that certain of our services may
infringe patents or other intellectual property of other parties. To date, none
of these has resulted in a material restriction on any use of our intellectual
property or has had a material adverse impact on our business. We may be unaware
of intellectual property rights of others that may, or may be claimed to, cover
our technology. Current or future claims could result in costly litigation and
divert the attention of management and key personnel from other business issues.
The complexity of the technology involved and the uncertainty of intellectual
property litigation increase these risks. Claims of intellectual property
infringement also might require us to enter into costly royalty or license
agreements to the extent necessary for the conduct of our business. However, we
may be unable to obtain royalty or license agreements on terms acceptable to us,
or at all. We also may be subject to significant damages or an injunction
against use of our proprietary or licensed systems. A successful claim of patent
or other intellectual property infringement against us could materially
adversely affect our business and profitability. We rely on a variety of
technology, primarily software that is licensed from third parties. Continued
use of this technology by us requires that we purchase new or additional
licenses from third parties. We cannot assure you that we can obtain those
third-party licenses needed for our business or that the third party technology
licenses that we do have will continue to be available to us on commercially
reasonable terms or at all. The loss or inability to maintain or obtain upgrades
to any of these technology licenses could result in delays or breakdowns in our
ability to continue developing and providing our services or to enhance and
upgrade our services.

WE MAY UNDERTAKE ADDITIONAL STRATEGIC ACQUISITIONS IN THE FUTURE AND ANY
DIFFICULTIES FROM INTEGRATING THESE ACQUISITIONS COULD DAMAGE OUR ABILITY TO
ATTAIN OR MAINTAIN PROFITABILITY.

We may acquire additional businesses and technologies that complement or augment
our existing businesses, services and technologies. Integrating any newly
acquired businesses or technologies could be expensive and time-consuming. We
may not be able to integrate any acquired business successfully. Moreover, we
may need to raise additional funds through public or private debt or equity
financing to acquire any businesses, which may result in dilution for
stockholders and the incurrence of indebtedness. We may not be able to operate
acquired businesses profitably or otherwise implement our growth strategy
successfully.
RISKS RELATED TO OUR COMPANY

THE MARKET PRICE OF OUR SHARES MAY EXPERIENCE EXTREME PRICE AND VOLUME
FLUCTUATIONS FOR REASONS OVER WHICH WE HAVE LITTLE CONTROL.

From time to time, the stock market has experienced, and is likely to continue
to experience, extreme price and volume fluctuations. Prices of securities of
Internet-related companies have been especially volatile and have often
fluctuated for reasons that are unrelated to the operating performance of the
affected companies. The market price of shares of our common stock has
fluctuated greatly since our initial public offering and could continue to
fluctuate due to a variety of factors.

WE HAVE BEEN SERVED WITH CLASS ACTION COMPLAINTS RELATING TO OUR INITIAL PUBLIC
OFFERING.

We have been served with several class action suits that relate to our
initial public ofering and allege that the underwriters of such offering
received undisclosed compensation in connection therewith. An adverse
resolution of one or more of these lawsuits, if not covered by insurance,
would have a material adverse effect on our financial position. For more
information see also "Legal Proceedings" below.

INTERNATIONAL GOVERNMENTAL REGULATION AND LEGAL UNCERTAINTIES COULD LIMIT OUR
ABILITY TO PROVIDE OUR SERVICES OR MAKE THEM MORE EXPENSIVE.

The regulatory treatment of Internet telephony and our enhanced services
offerings outside of the United States varies widely by country. A number of
countries currently prohibit or limit competition in the provision of
traditional voice telephony services. In some of those countries, licensed
telephony carriers as well as foreign regulators have questioned our legal
authority and/or the legal authority of our partners to offer our services. We
may face similar questions in additional countries. If we are forced to suspend
or discontinue operations as a result of foreign regulatory or legal challenges,
this could substantially affect our ability to achieve profitability. Some
countries prohibit, limit or regulate how companies provide Internet telephony.
Some countries have indicated they will evaluate proposed Internet telephony
service on a case-by-case basis and determine whether to regulate it as a voice
service or as another telecommunications service, and in doing so potentially
impose subsidies or other costs on Internet telephony providers. In addition,
many countries have not yet addressed Internet telephony in legislation or
regulations. Increased regulation of the Internet and/or Internet telephony
providers, or the prohibition of Internet telephony or related services,
including our enhanced offerings, in one or more countries, could limit our
ability to provide our services or make them more expensive. Finally,
international organizations such as the International Telecommunications Union
and the European Commission are continuing to examine whether Internet telephony
should continue to be subject to light regulation. Adverse recommendations by
these bodies could also limit our ability to provide services profitably. In
addition, as we make our services available in foreign countries, and as we work
to enable sales by our customers to end-users in foreign countries, these
countries may claim that we are required to qualify to do business in that
particular country, that we are otherwise subject to regulation, including
requirements to obtain authorization, or that we are prohibited in all cases
from conducting our business in that foreign country. We currently have
subsidiaries in Argentina, Australia, Brazil, Hong Kong, Israel, Japan, Mexico,
Peru, the United Kingdom and Singapore. We are authorized to provide services in
Belgium, Canada, France, Germany, Italy, Netherlands, Peru, Singapore, Spain,
Switzerland, and the United Kingdom, and the United States. Our failure to
qualify as a foreign corporation in a jurisdiction in which we are required to
do so or to comply with foreign laws and regulations could seriously restrict
our ability to provide services in these jurisdictions, or limit our ability to
enforce contacts in that jurisdiction. Our customers also currently are, or in
the future may become, subject to these same requirements. We cannot assure you
that our customers are currently in compliance with any
of these requirements or that they will be able to continue to comply with any
of these requirements. The failure of our customers to comply with applicable
laws and regulations could prevent us from being able to conduct business with
them, and would result in a loss of revenue for us. Additionally, it is possible
that countries may apply laws to transport services provided over the Internet,
including laws governing:

o        sales and other taxes, including payroll withholding applications;

o        user privacy;

o        labor and employment practices;

o        pricing controls;

o        characteristics and quality of products and services;

o        consumer protection;

o        cross-border commerce, including laws that would impose tariffs, duties
         and other import restrictions;

o        copyright, trademark and patent infringement; and

o        claims based on the nature and content of Internet materials, including
         defamation, negligence and the failure to meet necessary obligations.

If foreign governments or other bodies begin to regulate or prohibit Internet
telephony or our other services, this regulation could have a material adverse
effect on our ability to attain or maintain profitability.

THE TELECOMMUNICATIONS INDUSTRY IS SUBJECT TO DOMESTIC GOVERNMENTAL REGULATION
AND LEGAL UNCERTAINTIES THAT COULD PREVENT US FROM EXECUTING OUR BUSINESS PLAN.

While the Federal Communications Commission has tentatively decided that
information service providers, including Internet telephony providers, are
not telecommunications carriers for regulatory purposes, various companies
have challenged that decision. Some Congressional elements are dissatisfied
with the conclusions of the FCC and the FCC could impose greater or lesser
regulation on our industry. These regulations could mean imposition of
surcharges related to such things as access or universal service. We cannot
assure you that state government agencies will not increasingly regulate
Internet-related services. Increased regulation of the Internet may slow its
growth. This regulation may also negatively impact the cost of doing business
over the Internet and materially adversely affect our ability to attain or
maintain profitability. We are not licensed to offer traditional
telecommunications services in any U.S. state and we have not filed tariffs
for any service at the Federal Communications Commission or at any state
regulatory commission. Nonetheless, as more fully discussed in our Annual
Report on Form 10-K for the year ended December 31, 2000, under the caption
"Government Regulation", aspects of our operations may currently be, or
become, subject to state or federal regulations governing licensing,
universal service funding, disclosure of confidential communications or other
information, excise taxes, transactions restricted by U.S. embargo and other
reporting or compliance requirements. This regulation may also negatively
impact the cost of doing business and materially adversely affect our ability
to attain or maintain profitability.

PROVISIONS OF OUR GOVERNING DOCUMENTS AND DELAWARE LAW COULD DISCOURAGE
ACQUISITION PROPOSALS OR DELAY A CHANGE IN CONTROL.

Our certificate of incorporation and by-laws contain anti-takeover provisions,
including those listed below, that could make it more difficult for a third
party to acquire control of our company, even if that change in control may be
beneficial to stockholders:

o        our board of directors has the authority to issue common stock and
         preferred stock, and to determine the price, rights and preferences of
         any new series of preferred stock, without stockholder approval;

o        our board of directors is divided into three classes, each serving
         three-year terms;

o        our stockholders need a supermajority of votes to amend key provisions
         of our certificate of incorporation and by-laws;

o        there are limitations on who can call special meetings of stockholders;

o        our stockholders may not take action by written consent; and

o        our stockholders must provide specified advance notice to nominate
         directors or submit stockholder proposals.
In addition, provisions of Delaware law and our stock option plan may also
discourage, delay or prevent a change of control of our company or unsolicited
acquisition proposals.

                               ABOUT IBASIS, INC.

         We are a provider of advanced Internet-based voice communications. We
deliver toll-quality, international voice services and provide the
infrastructure for hosted communications solutions, including unified
communications and speech-enabled content, e-commerce and customer service
applications. We were incorporated in Delaware in 1996 and our principal
executive offices are located at 20 Second Avenue, Burlington, Massachusetts
01803. Our telephone number is (781) 505-7500 and our Web site is located at
www.ibasis.net. Information contained on our Web site is not a part of this
prospectus.
THE PRICEINTERACTIVE, INC. AMENDED AND RESTATED 2000 RESTRICTED STOCK PLAN

         On February 27, 2001, PriceInteractive, Inc., a Delaware
corporation, merged with and into our wholly-owned subsidiary, iBasis Speech
Solutions, Inc. and as a result we acquired all of the outstanding capital
stock of PriceInteractive. In connection with that merger we assumed the
PriceInteractive, Inc. Amended and Restated 2000 Restricted Stock Plan and
the awards previously granted under the Plan. This prospectus is part of a
registration statement under the Securities Act of 1933 that registers the
issuance of shares of our common stock pursuant to the grant of new awards
under the plan, and the resale of shares of our common stock issued under
this plan by the recipients thereof. The common stock underlying the awards
is subject to vesting conditions and is contingent upon the recipients
continued employment with iBasis. Generally, the restrictions on the shares
of iBasis common stock subject to the plan lapse as to 50% of a holder's
shares if that employee remains an employee of iBasis as of December 31,
2001, and any remaining restrictions lapse in full on December 31, 2002, if
the employee remains an employee of iBasis on such date. The lapse of these
vesting conditions is subject to acceleration upon certain events, including
the termination of such selling stockholder's employment by iBasis without
cause. In the event that an employee is terminated, any shares of common
stock subject to the plan and held by such employee which are not accelerated
may be canceled and reissued by iBasis at the direction of the administrator
of the plan to other former employees of PriceInteractive participating in
the plan.

                              SELLING STOCKHOLDERS

         As used in this prospectus, the term "selling stockholders" includes
the holders listed below as well as an undetermined number of additional
persons who are not affiliates of iBasis who may hold up to 1,000 shares of
iBasis common stock issued under the plan.

         Because the selling stockholders may sell all or a portion of the
shares of common stock beneficially owned by them, no estimate can be given as
to the number of shares of common stock that will be beneficially owned by the
selling stockholders after this registration statement is declared effective. In
addition, the selling stockholders may have sold, transferred or otherwise
disposed of, or may sell, transfer or otherwise dispose of, at any time or from
time to time since the date on which they provided to iBasis the information
regarding the shares of common stock beneficially owned by them, all or a
portion of the shares of common stock beneficially owned by them in transactions
exempt from the registration requirements of the Securities Act.

         The following table sets forth information regarding the beneficial
ownership of the shares by the selling stockholders as of the date of this
prospectus. None of the selling stockholders owns 1% or more of the
outstanding common stock and none of the selling stockholders will hold any
shares of common stock after the offering. As of August 14, 2001 there were
approximately 45.2 million shares of common stock issued and outstanding. All
of the shares to be sold by each selling stockholder hereunder are subject to
the vesting conditions described under "The PriceInteractive Amended and
Restated 2000 Restricted Stock Plan" above.
NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
Asokan, Ramachandran                                           3,590                 3,590
Bailey, Joe                                                    2,154                 2,154
Bartolomei, David                                              4,308                 4,308
Bittner, Steve                                                44,875                44,875
Blackburn, Carrie                                              2,512                 2,512
Buckman, Deborah                                               1,436                 1,436
Callahan, Colin                                               11,128                11,128
Cooke, Todd                                                    2,512                 2,512
Costenbader, Dave                                             21,540                21,540
Covert, Fred                                                   4,308                 4,308
NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
Crow, Steve                                                   10,770                10,770
Crum, Stacey                                                   2,154                 2,154
Davis, Judy                                                   10,770                10,770
Dhawan, Vishal                                               127,896               127,896
Digby, Amy                                                     2,692                 2,692
D'Souza, Marcius                                               5,744                 5,744
Embuscado, Arnel                                               3,590                 3,590
Ford, Eugene (Dan)                                             4,308                 4,308
Fredericks, Steve                                              1,795                 1,795
Godfrey, Charles                                               4,308                 4,308
Godfrey, Hedyeh                                                4,308                 4,308
Gray, Josh                                                    19,745                19,745
Green, David                                                   1,076                 1,076
Hamilton, John                                                 1,436                 1,436
Hanson, Bruce                                                 12,026                12,026
Herring, Becky                                                 1,256                 1,256
Hibbard, Mike                                                  9,872                 9,872
Higgins, Jacqui                                                2,154                 2,154
Hodges, Steve                                                  1,257                 1,257
Hoehl, Karen                                                   4,308                 4,308
Hyde, Sara                                                     1,346                 1,346
Jacobs, Sarah                                                 10,770                10,770
Jian, David                                                    1,795                 1,795
Kang, Michael                                                  1,795                 1,795
Kulesa, Susan                                                  4,667                 4,667
Kumpf, Tom                                                     9,155                 9,155
Langhorne, Darren                                             11,488                11,488
Larison, Beverly                                               1,257                 1,257
Larson, Jinann                                                 1,257                 1,257
Lenhard, Chris                                                 1,077                 1,077
Lindsey, Lynn                                                  1,077                 1,077
Logan, Paul                                                   43,080                43,080
Mentall, David                                                 1,256                 1,256
Meredith, Susan                                                1,795                 1,795
Michael, Karina                                                8,975                 8,975
Michallas, George                                              8,616                 8,616
Moore, Dan                                                   185,337               185,337
Patterson, James                                               4,308                 4,308
Pinheiro, Karen                                                1,256                 1,256
Rao, Kanchana                                                  1,436                 1,436
Ratay, Bob                                                     1,616                 1,616
Riegle, Jill                                                   8,975                 8,975
Rodgers, Tad                                                  52,504                52,504
Saeger, Terry                                                 17,770                17,770
Sage, Laurie                                                   2,512                 2,512
Sahoo, J Ramesh                                                2,692                 2,692
Schlimmee, Kurt                                               28,002                28,002
Shields, Bob                                                   1,256                 1,256
Shomo, Milton                                                 10,052                10,052
Siegler, Ben                                                   6,102                 6,102
Sillah, Bintou                                                 1,076                 1,076
Sokol, Nellie                                                 10,770                10,770
NAME OF SELLING                         SHARES BENEFICIALLY OWNED PRIOR TO         SHARES
     STOCKHOLDERS                                      OFFERING (1)                   OFFERED
   ----------------                         ----------------------------------       --------
Stathopolous, George                                           2,154                 2,154
Sussman, Chris                                                 2,154                 2,154
Thompson, Aaron                                               26,207                26,207
Upadhyaya, Vasudha                                             1,795                 1,795
Watson, Joe                                                    7,180                 7,180
Weiss, Keith                                                  35,900                35,900
Whetzel, Jean                                                  1,975                 1,975
Whittle, Mark                                                 23,334                23,334
Wilkins, Jeff                                                 15,796                15,796
Williams, Charla                                               8,616                 8,616
Wilson, Tim                                                    2,872                 2,872
Wooding, Michele                                               4,128                 4,128
Wright, Kathy                                                 27,284                27,284
Zalubas, Mark                                                  8,975                 8,975
Zhu, Ziaoquing                                                 2,154                 2,154
Other non-affiliates of iBasis                                41,840                41,840

         TOTAL                                               987,262               987,262
         =====                                               =======               =======
(1)      Beneficial ownership is determined in accordance with Rule 13d-3(d)
         promulgated by the SEC under the Securities and Exchange Act of 1934,
         as amended.

                              PLAN OF DISTRIBUTION

         The shares offered hereby by the selling stockholders may be sold
from time to time by the selling stockholders as a principal or through one
or more brokers, dealers or agents from time to time in one or more
transactions, which may involve crosses or block transactions, in special
offerings, in negotiated transactions, or otherwise. Any of these
transactions may be effected at market prices prevailing at the time of sale,
at prices related to prevailing market prices, at varying prices determined
at the time of sale or at negotiated or fixed prices, in each case as
determined by the selling stockholders or by agreement between the selling
stockholders and brokers, dealers or agents, or purchasers. The selling
stockholders may effect transactions by selling the shares directly to
purchasers or by selling shares to or through brokers or dealers and these
brokers or dealers may receive compensation in the form of discounts,
concessions or commissions from the selling stockholders or the purchasers of
the shares for whom these brokers or dealers may act as agent, or to whom
they sell as principal, or both, which compensation to a particular broker or
dealer might be in excess of customary commissions or be changed from time to
time. The selling stockholders and any brokers, dealers or agents who
participate in a sale of the shares may be deemed "underwriters" within the
meaning of Section 2(11) of the Securities Act of 1933 and the commissions
paid or discounts allowed to any of these brokers, dealers or agents in
addition to any profits received on resale of the shares if any of these
brokers, dealers or agents should purchase any shares as a principal may be
deemed to be underwriting discounts or commissions under the Securities Act
of 1933.

         In addition, any shares covered by this prospectus that qualify for
sale pursuant to Rules 701 and 144 of the Securities Act may be sold under Rules
701 and 144 rather than pursuant to the prospectus. A selling stockholder also
may pledge the shares as collateral for margin accounts and the shares may be
resold pursuant to the terms of these accounts.

         We will pay all of the expenses incident to the registration of the
shares to the public hereunder other than commissions, fees and discounts of
brokers, dealers, agents and the selling stockholders' attorney's fees.

                                 USE OF PROCEEDS

         We will not receive any of the proceeds from the sale of any of the
shares by the selling stockholders.
LEGAL PROCEEDINGS

         Beginning August 1, 2001, we were served with several class action
complaints that were filed in the United States District Court for the Southern
District of New York against us and several of our officers, directors, and
former officers and directors, as well as against the investment banking firms
that underwrote our November 11, 1999 initial public offering of common stock.
The complaints were filed on behalf of persons who purchased our common stock
during different time periods, all beginning on or after November 10, 1999 and
ending on or before December 6, 2000. The complaints are similar to each other
and to hundreds of other complaints filed recently against other issuers and
their underwriters, and allege violations of the Securities Act of 1933 and the
Securities Exchange Act of 1934 primarily based on the assertion that there was
undisclosed compensation received by our underwriters in connection with our
initial public offering.

         Although neither iBasis nor the individual defendants have filed
answers in any of these matters, iBasis believes that it and the individual
defendants have meritorious defenses to the claims made in the complaints and
intends to contest the lawsuits vigorously. However, there can be no assurance
that we will be successful in such a defense. In addition, even though we have
insurance and contractual protections that could cover some or all of the
potential damages in these cases, or amounts that we might have to pay in
settlement of these cases, an adverse resolution of one or more of these
lawsuits could have a material adverse affect on our financial position and
results of operation in the period in which the lawsuits are resolved. Given the
early stage of the proceedings, we are not presently able to estimate potential
losses, if any, related to the lawsuits.

                                     EXPERTS

         The financial statements of iBasis, Inc. incorporated by reference
in this prospectus and elsewhere in the Registration Statement, have been
audited by Arthur Andersen LLP, independent public accountants, as indicated
in their report with respect thereto, and are incorporated by reference
herein in reliance upon the authority of said firm as experts in giving said
reports.

         The financial statements of PriceInteractive, Inc. incorporated by
reference in this prospectus and elsewhere in the Registration Statement have
been audited by Arthur Andersen LLP, independent public accountants, as
indicated in their report with respect thereto, and are included herein in
reliance upon the authority of said firm as experts in giving said reports.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3:  INCORPORATION OF DOCUMENTS BY REFERENCE

         We incorporate by reference the following documents filed by us with
the Securities and Exchange Commission:
PERIOD OR DATE
The description of our common stock contained in our registration statement
filed with the SEC under Section 12(g) of the Securities Exchange Act, including
any amendment or report filed for the purpose of updating such description .....      Filed August 24, 1999

Annual Report on Form 10-K......................................................      Filed February 26, 2001

Current Report on Form 8-K......................................................      Filed March 14, 2001

Quarterly Report on Form 10-Q...................................................      Filed August 14, 2001
In addition, all documents subsequently filed by us pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of
a post-effective amendment which indicates that all securities offered hereby
have been sold or which deregisters all of such securities then remaining
unsold, shall be deemed to be incorporated by reference into this Registration
Statement and to be a part hereof from the date of filing of such documents.

ITEM 4:  DESCRIPTION OF SECURITIES

         Not applicable.

ITEM 5:  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not applicable.

ITEM 6:  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation Law empowers a Delaware
corporation to indemnify its officers and directors and specified other persons
to the extent and under the circumstances set forth therein.

         The Amended and Restated Certificate of Incorporation and the Amended
and Restated By-Laws of the Company, copies of which have been filed as Exhibits
3.1 and 3.2 to iBasis' Annual Report on Form 10-K for its fiscal year ended
December 31, 2000, provide for advancement of expenses and indemnification of
officers and directors of iBasis and specified other persons against liabilities
and expenses incurred by any of them in certain stated proceedings and under
certain stated conditions to the fullest extent permissible under Delaware law.

         We intend to maintain insurance for the benefit of our directors and
officers insuring these persons against certain liabilities, including
liabilities under the securities laws.
ITEM 7:  EXEMPTION FROM REGISTRATION CLAIMED.

         The issuance of the shares of restricted stock covered by this
Registration Statement and offered for resale by the prospectus included herein
were made in reliance on, among other applicable exemptions from registration,
Rule 701 of the Securities Act.

ITEM 8:  EXHIBITS

         The following exhibits are filed as part of this Registration
Statement:

         4.1      Specimen Certificate for shares of the Registrant's common
                  stock (incorporated by reference from Exhibit Specimen
                  Certificate for shares of the Registrant's common stock to the
                  Registrant's Registration Statement on Form S-1 (file no.
                  333-85545)).

         4.2      The PriceInteractive Amended and Restated 2000 Restricted
                  Stock Plan.

         4.3      Form of Award Agreement issued under the PriceInteractive
                  Amended and Restated 2000 Restricted Stock Plan.

         5        Opinion of Bingham Dana LLP, counsel to the Registrant,
                  regarding the legality of the shares of common stock
                  registered hereunder.

         23.1     Consent of Arthur Andersen LLP.

         23.2     Consent of Arthur Andersen LLP.

         23.3     Consent of Bingham Dana LLP, counsel to the Registrant
                  (included in Exhibit 5).

         24       Power of Attorney (contained on the signature page of this
                  Registration Statement).

------------------------------

ITEM 9:  UNDERTAKINGS

         The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement to include any
material information with respect to the plan of distribution not previously
disclosed in the Registration Statement or any material change to such
information in the Registration Statement;

         (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
Registration Statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof;

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering;

         (4) That, for purposes of determining any liability under the
Securities Act of 1933, each filing of the Registrant's annual report pursuant
to Section 13(a) or 15(d) of the Exchange Act that is incorporated by reference
in the Registration Statement shall be deemed to be a new Registration Statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof; and

         (5) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
SIGNATURES

         Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in Burlington, Massachusetts on the 17th day of August, 2001.

                                     iBASIS, INC

                                     By:  /s/ OFER GNEEZY
                                          -------------------------------------
                                          Ofer Gneezy
                                          President and Chief Executive Officer

                                POWER OF ATTORNEY

         We, the undersigned officers and Directors of iBasis, Inc., hereby
severally constitute and appoint Ofer Gneezy and Jonathan Draluck, and each of
them singly, our true and lawful attorneys with full power to them, and each of
them singly, to sign for us and in our names in the capacities indicated below
the Registration Statement on Form S-8 filed herewith and any and all
pre-effective and post-effective amendments to said Registration Statement, and
generally to do all such things in our names and on our behalf in our capacities
as officers and Directors to enable iBasis to comply with the provisions of the
Securities Act, and all requirements of the Securities and Exchange Commission,
hereby ratifying and confirming our signatures, as they may be signed by our
said attorneys or any of them, to said Registration Statement and any and all
amendments thereto.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated.
SIGNATURE                                                          TITLE                           DATE
President, Chief Executive Officer
/s/ OFER GNEEZY                                       and Director (Principal Executive
------------------------------------                  Officer)
    Ofer Gneezy

                                                      Vice President, Corporate
                                                      Development, Interim Chief Financial
/s/ D.J. LONG                                         Officer (Principal Financial and
------------------------------------                  Accounting Officer)
    D.J. Long

/s/ GORDON J.  VANDERBRUG                             Executive Vice President and Director
------------------------------------
    Gordon J.  VanderBrug

/s/ DANIEL PRICE                                      Director
------------------------------------
    Daniel Price

/s/ CHARLES N.  CORFIELD                              Director
------------------------------------
    Charles N.  Corfield

/s/ CHARLES M.  SKIBO                                 Director
------------------------------------
    Charles M. Skibo

/s/ CARL REDFIELD                                     Director
-------------------------------------
    Carl Redfield

/s/ W. FRANK KING                                     Director
--------------------------
    W. Frank King
EXHIBIT INDEX

  EXHIBIT NO                 DESCRIPTION OF DOCUMENTS
  ----------                 ------------------------

         4.1      Specimen Certificate for shares of the Registrant's common
                  stock (incorporated by reference from Exhibit Specimen
                  Certificate for shares of the Registrant's common stock to the
                  Registrant's Registration Statement on Form S-1 (file no.
                  333-85545)).

         4.2      The PriceInteractive Amended and Restated 2000 Restricted
                  Stock Plan.

         4.3      Form of Award Agreement issued under the PriceInteractive
                  Amended and Restated 2000 Restricted Stock Plan.

         5        Opinion of Bingham Dana LLP, counsel to the Registrant,
                  regarding the legality of the shares of common stock
                  registered hereunder.

         23.1     Consent of Arthur Andersen LLP.

         23.2     Consent of Arthur Andersen LLP.

         23.3     Consent of Bingham Dana LLP, counsel to the Registrant
                  (included in Exhibit 5).

         24       Power of Attorney (contained on the signature page of this
                  Registration Statement).

---------------------------