<PAGE>   1
     As filed with the Securities and Exchange Commission on July 14, 2000
                                                 Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                                    8X8, INC.
             (Exact name of Registrant as specified in its charter)

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

              DELAWARE                                      77-0142404
  (State or other jurisdiction of                         (I.R.S. Employer
   incorporation or organization)                      Identification Number)

                           2445 MISSION COLLEGE BLVD.
                              SANTA CLARA, CA 95054
                    (Address of principal executive offices)

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

            AMENDED AND RESTATED 1999 NONSTATUTORY STOCK OPTION PLAN
   UFORCE COMPANY - SOCIETE UFORCE AMENDED AND RESTATED 1999 STOCK OPTION PLAN

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

                                   PAUL VOOIS
                           CHIEF EXECUTIVE OFFICER AND
                              CHAIRMAN OF THE BOARD
                                    8X8, INC.
                           2445 MISSION COLLEGE BLVD.
                              SANTA CLARA, CA 95054
                                 (408) 727-1885
            (Name, address and telephone number of agent for service)

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

                                    Copy to:
                             John T. Sheridan, Esq.
                     Wilson Sonsini Goodrich & Rosati, P.C.
                               650 Page Mill Road
                           Palo Alto, California 94304

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

<TABLE>
<CAPTION>
==================================================================================================================
                                          CALCULATION OF REGISTRATION FEE
==================================================================================================================
                                                            Proposed Maximum   Proposed Maximum
                                              Amount to be   Offering Price       Aggregate          Amount of
    Title of Securities to be Registered       Registered      Per Share        Offering Price    Registration Fee
------------------------------------------------------------------------------------------------------------------
<S>                                           <C>           <C>                <C>                <C>
Common Stock, $0.001 par value per share:
Issued under 8x8, Inc. Amended and Restated
1999 Nonstatutory Stock Option Plan .......      3,600,000     $  9.89(1)        $35,604,000          $ 9,400

Common Stock, $0.001 par value per share:
Issued under UForce Company - Societe
UForce Amended and Restated 1999 Stock
Option Plan ...............................      1,023,898     $ 10.21(2)        $10,453,998(2)       $ 2,760
</TABLE>

(1) Estimated in part in accordance with Rule 457(c) solely for the purpose of
    calculating the registration fee based upon the average of the high and low
    prices of the Common Stock as reported on the Nasdaq National Market on July
    11, 2000, which was $10.375 per share, for a total of 2,632,985 shares not
    yet subject to outstanding options under the plan, and in part in accordance
    with Rule 457(h) for a total of 967,015 shares subject to outstanding
    options under the plan with a weighted average exercise price of $8.60 per
    share. The proposed offering price per share is the weighted average of the
    foregoing estimates.

(2) Estimated in accordance with Rule 457(h) solely for the purpose of
    calculating the registration fee based upon the price at which the options
    may be exercised.

================================================================================
<PAGE>   2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3. Incorporation of Documents by Reference

        8x8, Inc. (the "Company") hereby incorporates by reference in this
registration statement the following documents:

        (a) The Company's Annual Report on Form 10-K for the fiscal year ended
March 31, 2000.

        (b) All other reports filed pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act") since the end
of the fiscal year covered by the Company document referred to in (a) above.

        (c) The description of the Company's Common Stock contained in the
Company's Registration Statement on Form 8-A (No. 000-21783) filed pursuant to
Section 12 of the Exchange Act, including any amendment or report filed for the
purpose of updating such description.

        All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment to this registration statement which indicates that all
securities offered hereby have been sold or which deregisters all securities
remaining unsold, shall be deemed to be incorporated by reference in 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 authorizes a court
to award, or a corporation's board of directors to grant, indemnity to directors
and officers in terms sufficiently broad to permit such indemnification under
certain circumstances for liabilities (including reimbursement for expenses
incurred) arising under the Securities Act. Article 8 of the Company's Amended
and Restated Certificate of Incorporation and Article 6 of the Bylaws of the
Company provide for indemnification of certain agents to the maximum extent
permitted by the Delaware General Corporation Law. Persons covered by these
indemnification provisions include current and former directors, officers,
employees and other agents of the Company, as well as persons who serve at the
request of the Company as directors, officers, employees or agents of another
enterprise. In addition, the Company has entered into agreements with its
officers and directors which require the Company to indemnify its officers and
directors to the maximum extent permitted under Delaware law.



                                      II-1
<PAGE>   3

Item 7. Exemption From Registration Claimed

        Not applicable.

Item 8. Exhibits

<TABLE>
<S>            <C>
       4.1     Amended and Restated 1999 Nonstatutory Stock Option Plan

       4.2     UForce Company - Societe UForce Amended and Restated 1999 Stock
               Option Plan

       5.1     Opinion of counsel as to legality of securities being registered

      23.1     Consent of Independent Accountants

      23.2     Consent of Counsel (contained in Exhibit 5.1)

      24.1     Power of Attorney (contained on signature page)
</TABLE>

Item 9. Undertakings

        (a) Rule 415 Offering The undersigned Company 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 of 1933, as amended, 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.

        (b) Filing incorporating subsequent Exchange Act documents by reference

        The undersigned Company hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, as amended, each
filing of the Company's annual report pursuant to section 13(a) or section 15(d)
of the Exchange Act (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to section 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.



                                       2
<PAGE>   4

        (c) Request for acceleration of effective date or filing of registration
statement on Form S-8

        Insofar as indemnification for liabilities arising under the Securities
Act of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Company pursuant to the foregoing provisions, or otherwise, the
Company has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Company of expenses incurred or
paid by a director, officer or controlling person of the Company 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 Company 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 Act and will be governed by the final adjudication of
such issue.



                                       3
<PAGE>   5

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Company 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 the City of Santa Clara, State of California, on July 13,
2000.

                                   8x8, Inc.

                                   By:   /s/ Paul Voois
                                        ----------------------------------------
                                        Paul Voois
                                        Chief Executive Officer and Chairman of
                                        the Board



                                       4
<PAGE>   6

                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Paul Voois and David M. Stoll jointly and
severally, his attorneys-in-fact, each with the power of substitution, for him
in any and all capacities, to sign any amendments to this Registration Statement
on Form S-8, and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

<TABLE>
<CAPTION>
             Signature                                 Title                         Date
---------------------------------    ----------------------------------------   -------------
<S>                                  <C>                                        <C>

 /s/ Paul Voois                      Chairman of the Board and Chief            July 13, 2000
---------------------------------    Executive Officer and Director
Paul Voois                           (Principal Executive Officer)

 /s/ David M. Stoll                  Chief Financial Officer and Vice           July 13, 2000
---------------------------------    President, Finance (Principal Financial
David M. Stoll                       and Accounting Officer)

 /s/ Lee Camp                        Director                                   July 13, 2000
---------------------------------
Lee Camp

                                     Director
---------------------------------
Bernd Girod

 /s/ Guy L. Hecker                   Director                                   July 13, 2000
---------------------------------
Guy L. Hecker

                                     Director
---------------------------------
Christos Lagomichos

 /s/ Joe Markee                      Director                                   July 13, 2000
---------------------------------
Joe Markee

 /s/ William Tai                     Director                                   July 13, 2000
---------------------------------
William Tai
</TABLE>



                                       5
<PAGE>   7

                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
  Exhibit
  Number
<S>          <C>
    4.1      Amended and Restated 1999 Nonstatutory Stock Option Plan

    4.2      UForce Company - Societe UForce Amended and Restated 1999 Stock
             Option Plan

    5.1      Opinion of counsel as to legality of securities being registered

   23.1      Consent of Independent Accountants

   23.2      Consent of Counsel (contained in Exhibit 5.1)

   24.1      Power of Attorney (contained on signature page)
</TABLE>



                                       6
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{"company-data": {"conformed-name": "8X8 INC", "cik": "0001023731", "assigned-sic": "3674", "irs-number": "770142404", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-41594", "film-number": "674218"}, "business-address": {"street1": "2445 MISSION COLLEGE BLVD", "city": "SANTA CLARA", "state": "CA", "zip": "95054", "phone": "4087271885"}, "mail-address": {"street1": "2445 MISSION COLLEGE BLVD", "city": "SANTA CLARA", "state": "CA", "zip": "95054"}}
1
     As filed with the Securities and Exchange Commission on July 14, 2000
                                                 Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                                    8X8, INC.
             (Exact name of Registrant as specified in its charter)

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

              DELAWARE                                      77-0142404
  (State or other jurisdiction of                         (I.R.S. Employer
   incorporation or organization)                      Identification Number)

                           2445 MISSION COLLEGE BLVD.
                              SANTA CLARA, CA 95054
                    (Address of principal executive offices)

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

            AMENDED AND RESTATED 1999 NONSTATUTORY STOCK OPTION PLAN
   UFORCE COMPANY - SOCIETE UFORCE AMENDED AND RESTATED 1999 STOCK OPTION PLAN

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

                                   PAUL VOOIS
                           CHIEF EXECUTIVE OFFICER AND
                              CHAIRMAN OF THE BOARD
                                    8X8, INC.
                           2445 MISSION COLLEGE BLVD.
                              SANTA CLARA, CA 95054
                                 (408) 727-1885
            (Name, address and telephone number of agent for service)

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

                                    Copy to:
                             John T. Sheridan, Esq.
                     Wilson Sonsini Goodrich & Rosati, P.C.
                               650 Page Mill Road
                           Palo Alto, California 94304

                               ------------------
==================================================================================================================
                                          CALCULATION OF REGISTRATION FEE
==================================================================================================================
                                                            Proposed Maximum   Proposed Maximum
                                              Amount to be   Offering Price       Aggregate          Amount of
    Title of Securities to be Registered       Registered      Per Share        Offering Price    Registration Fee
------------------------------------------------------------------------------------------------------------------
Common Stock, $0.001 par value per share:
Issued under 8x8, Inc. Amended and Restated
1999 Nonstatutory Stock Option Plan .......      3,600,000     $  9.89(1)        $35,604,000          $ 9,400

Common Stock, $0.001 par value per share:
Issued under UForce Company - Societe
UForce Amended and Restated 1999 Stock
Option Plan ...............................      1,023,898     $ 10.21(2)        $10,453,998(2)       $ 2,760
(1) Estimated in part in accordance with Rule 457(c) solely for the purpose of
    calculating the registration fee based upon the average of the high and low
    prices of the Common Stock as reported on the Nasdaq National Market on July
    11, 2000, which was $10.375 per share, for a total of 2,632,985 shares not
    yet subject to outstanding options under the plan, and in part in accordance
    with Rule 457(h) for a total of 967,015 shares subject to outstanding
    options under the plan with a weighted average exercise price of $8.60 per
    share. The proposed offering price per share is the weighted average of the
    foregoing estimates.

(2) Estimated in accordance with Rule 457(h) solely for the purpose of
    calculating the registration fee based upon the price at which the options
    may be exercised.

================================================================================
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference

        8x8, Inc. (the "Company") hereby incorporates by reference in this
registration statement the following documents:

        (a) The Company's Annual Report on Form 10-K for the fiscal year ended
March 31, 2000.

        (b) All other reports filed pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act") since the end
of the fiscal year covered by the Company document referred to in (a) above.

        (c) The description of the Company's Common Stock contained in the
Company's Registration Statement on Form 8-A (No. 000-21783) filed pursuant to
Section 12 of the Exchange Act, including any amendment or report filed for the
purpose of updating such description.

        All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment to this registration statement which indicates that all
securities offered hereby have been sold or which deregisters all securities
remaining unsold, shall be deemed to be incorporated by reference in 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 authorizes a court
to award, or a corporation's board of directors to grant, indemnity to directors
and officers in terms sufficiently broad to permit such indemnification under
certain circumstances for liabilities (including reimbursement for expenses
incurred) arising under the Securities Act. Article 8 of the Company's Amended
and Restated Certificate of Incorporation and Article 6 of the Bylaws of the
Company provide for indemnification of certain agents to the maximum extent
permitted by the Delaware General Corporation Law. Persons covered by these
indemnification provisions include current and former directors, officers,
employees and other agents of the Company, as well as persons who serve at the
request of the Company as directors, officers, employees or agents of another
enterprise. In addition, the Company has entered into agreements with its
officers and directors which require the Company to indemnify its officers and
directors to the maximum extent permitted under Delaware law.

                                      II-1
3

Item 7. Exemption From Registration Claimed

        Not applicable.

Item 8. Exhibits
4.1     Amended and Restated 1999 Nonstatutory Stock Option Plan

       4.2     UForce Company - Societe UForce Amended and Restated 1999 Stock
               Option Plan

       5.1     Opinion of counsel as to legality of securities being registered

      23.1     Consent of Independent Accountants

      23.2     Consent of Counsel (contained in Exhibit 5.1)

      24.1     Power of Attorney (contained on signature page)
Item 9. Undertakings

        (a) Rule 415 Offering The undersigned Company 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 of 1933, as amended, 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.

        (b) Filing incorporating subsequent Exchange Act documents by reference

        The undersigned Company hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, as amended, each
filing of the Company's annual report pursuant to section 13(a) or section 15(d)
of the Exchange Act (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to section 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.

                                       2
4

        (c) Request for acceleration of effective date or filing of registration
statement on Form S-8

        Insofar as indemnification for liabilities arising under the Securities
Act of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Company pursuant to the foregoing provisions, or otherwise, the
Company has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Company of expenses incurred or
paid by a director, officer or controlling person of the Company 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 Company 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 Act and will be governed by the final adjudication of
such issue.

                                       3
5

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Company 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 the City of Santa Clara, State of California, on July 13,
2000.

                                   8x8, Inc.

                                   By:   /s/ Paul Voois
                                        ----------------------------------------
                                        Paul Voois
                                        Chief Executive Officer and Chairman of
                                        the Board

                                       4
6

                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Paul Voois and David M. Stoll jointly and
severally, his attorneys-in-fact, each with the power of substitution, for him
in any and all capacities, to sign any amendments to this Registration Statement
on Form S-8, and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.
Signature                                 Title                         Date
---------------------------------    ----------------------------------------   -------------
/s/ Paul Voois                      Chairman of the Board and Chief            July 13, 2000
---------------------------------    Executive Officer and Director
Paul Voois                           (Principal Executive Officer)

 /s/ David M. Stoll                  Chief Financial Officer and Vice           July 13, 2000
---------------------------------    President, Finance (Principal Financial
David M. Stoll                       and Accounting Officer)

 /s/ Lee Camp                        Director                                   July 13, 2000
---------------------------------
Lee Camp

                                     Director
---------------------------------
Bernd Girod

 /s/ Guy L. Hecker                   Director                                   July 13, 2000
---------------------------------
Guy L. Hecker

                                     Director
---------------------------------
Christos Lagomichos

 /s/ Joe Markee                      Director                                   July 13, 2000
---------------------------------
Joe Markee

 /s/ William Tai                     Director                                   July 13, 2000
---------------------------------
William Tai
5
7

                                  EXHIBIT INDEX
Exhibit
  Number
4.1      Amended and Restated 1999 Nonstatutory Stock Option Plan

    4.2      UForce Company - Societe UForce Amended and Restated 1999 Stock
             Option Plan

    5.1      Opinion of counsel as to legality of securities being registered

   23.1      Consent of Independent Accountants

   23.2      Consent of Counsel (contained in Exhibit 5.1)

   24.1      Power of Attorney (contained on signature page)
6