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<title>Document</title></head><body><div id="if285563679054f6287edd9e6467fe6d6_1"></div><div style="min-height:36pt;width:100%"><div style="text-indent:18pt"><font><br></font></div></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">As filed with the U.S. Securities and Exchange Commission on February 29, 2024</font></div><div style="margin-bottom:3pt;text-align:right"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Registration No. 333-</font></div><div style="margin-bottom:6pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:100.000%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">UNITED STATES</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">SECURITIES AND EXCHANGE COMMISSION</font></div><div style="margin-bottom:3pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">WASHINGTON, D.C. 20549</font></div><div style="text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:30.555%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">FORM S-8</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">REGISTRATION STATEMENT</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">UNDER</font></div><div style="margin-bottom:3pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:700;line-height:120%">THE SECURITIES ACT OF 1933</font></div><div style="text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:30.555%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:16pt;font-weight:700;line-height:120%">Klaviyo, Inc.</font></div><div style="margin-bottom:3pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(Exact name of registrant as specified in its charter)</font></div><div style="margin-bottom:12pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:30.555%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="margin-bottom:12pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:83.333%"><tr><td style="width:1.0%"></td><td style="width:32.233%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:32.233%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:32.234%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="margin-top:2.65pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Delaware </font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">(State or other jurisdiction of incorporation or organization)</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">46-0989964 <br>(I.R.S. Employer Identification No.)</font></td></tr><tr style="height:9pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">125 Summer Street, 6th Floor</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Boston, MA 02110</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">(Address of Principal Executive Offices and Zip Code)</font></div></td><td colspan="3" style="padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">2023 Stock Option and Incentive Plan </font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">2023 Employee Stock Purchase Plan </font></div><div style="margin-bottom:3pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(Full titles of the plans)</font></div><div style="margin-bottom:12pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:30.555%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Andrew Bialecki</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Co-Founder, Chief Executive Officer</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Klaviyo, Inc.</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">125 Summer Street, 6th Floor</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">Boston, MA 02110</font></div><div style="margin-bottom:12pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(Name and address of agent for service)&#160;</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(617) 213-1788</font></div><div style="margin-bottom:3pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:120%">(Telephone number, including area code, of agent for service)</font></div><div style="margin-bottom:6pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:30.555%"><tr><td style="width:1.0%"></td><td style="width:98.900%"></td><td style="width:0.1%"></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr></table></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-style:italic;font-weight:400;line-height:120%">Copies to&#58;</font></div><div style="margin-bottom:12pt;text-align:center"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:85.138%"><tr><td style="width:1.0%"></td><td style="width:38.051%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:20.596%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:38.053%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:middle"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Craig M. Schmitz</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Bradley C. Weber</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Kim S. de Glossop</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Kristin A. Gerber</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Goodwin Procter&#160;LLP</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">100 Northern Avenue</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Boston, MA 02210</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">(617) 570-1000</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:middle"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Landon R. Edmond</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Cameron S. Vermette</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Klaviyo, Inc.</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">125 Summer Street, 6th Floor</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">Boston, MA 02110</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:700;line-height:100%">(617) 213-1788</font></div></td></tr></table></div><div style="margin-bottom:6pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of &#8220;large accelerated filer,&#8221; &#8220;accelerated filer,&#8221; &#8220;smaller reporting company&#8221; and &#8220;emerging growth company&#8221; in Rule&#160;12b-2 of the Exchange Act.</font></div><div><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:100.000%"><tr><td style="width:1.0%"></td><td style="width:21.122%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:52.094%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:21.122%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:2.162%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Large accelerated filer </font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">&#9744;</font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Accelerated filer </font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">&#9744;</font></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Non-accelerated filer </font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Wingdings',sans-serif;font-size:9pt;font-weight:400;line-height:100%">&#253;</font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Smaller reporting company </font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">&#9744;</font></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:100%">Emerging growth company </font></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Wingdings',sans-serif;font-size:9pt;font-weight:400;line-height:100%">&#253;</font></td></tr></table></div><div><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. &#9744;</font></div><div style="height:36pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div><div id="if285563679054f6287edd9e6467fe6d6_4"></div><hr style="page-break-after:always"><div style="min-height:72pt;width:100%"><div style="text-indent:18pt"><font><br></font></div></div><div style="margin-bottom:9pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:112%">EXPLANATORY NOTE </font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">Klaviyo, Inc. (the &#8220;Registrant&#8221;) is filing this Registration Statement on Form S-8 (the &#8220;Registration Statement&#8221;) with the Securities and Exchange Commission (the &#8220;Commission&#8221;) to register (i) </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">12,968,292</font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> additional shares of its Series A Common Stock, par value $0.001 per share (the &#8220;Series A common stock&#8221;), under the 2023 Stock Option and Incentive Plan (the &#8220;2023 Plan&#8221;) and (ii) </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">2,593,658</font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> additional shares of its Series A common stock under the 2023 Employee Stock Purchase Plan (the &#8220;2023 ESPP&#8221;), pursuant to the provisions of the 2023 Plan and 2023 ESPP, respectively, which provide for an automatic increase in the number of shares reserved and available for issuance under such plans on January 1, 2024, </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">and each January 1 thereafter until each of the plans terminate respective to their terms</font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">.</font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">This Registration Statement registers additional securities of the same class as other securities of the Registrant for which a Registration Statement on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023032563/klaviyoincs-8.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Form S-8</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> </font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">filed with the Commission on September 19, 2023 </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">(File No. 333-</font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">274591</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">) is effective. </font><font style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> Pursuant to General Instruction&#160;E of Form S-8, the contents of the Registration Statement referenced above are hereby incorporated by reference in this Registration Statement to the extent not replaced hereby.</font></div><div id="if285563679054f6287edd9e6467fe6d6_7"></div><div style="margin-bottom:9pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">PART II</font></div><div style="margin-bottom:9pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</font></div><div id="if285563679054f6287edd9e6467fe6d6_10"></div><div style="margin-bottom:9pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Item 3.</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:7.7pt;text-decoration:underline">Incorporation of Documents by Reference</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">.</font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The following documents filed with the Commission by the Registrant are incorporated by reference into this Registration Statement&#58;</font></div><div style="margin-bottom:9pt;padding-left:36pt;text-align:justify;text-indent:-18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">(a)</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;padding-left:6.91pt">The contents of the Registration Statement on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023032563/0001628280-23-032563-index.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Form S-8</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> filed with the Commission on September 19, 2023 (File No. 333-274591)&#59;</font></div><div style="margin-bottom:9pt;padding-left:36pt;text-align:justify;text-indent:-18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">(b)</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;padding-left:6.34pt">The Registrant&#8217;s Annual Report on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/0001835830-24-000022-index.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Form 10-K</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> for the year ended December 31, 2023, filed with the Commission on February 29, 2024&#59; </font></div><div style="margin-bottom:9pt;padding-left:36pt;text-align:justify;text-indent:-18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">(c)</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;padding-left:6.91pt">All other reports filed by the Registrant pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934, as amended (the &#8220;Exchange Act&#8221;), since December 31, 2023&#59; and</font></div><div style="margin-bottom:9pt;padding-left:36pt;text-align:justify;text-indent:-18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">(d)</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;padding-left:6.34pt">The description of the Registrant&#8217;s Series A common stock contained in the Registrant&#8217;s Registration Statement on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023032362/0001628280-23-032362-index.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Form 8-A</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> (File No. 001-41806) filed with the Commission on September 15, 2023 under Section 12(b) of the Exchange Act, updated by </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/a10-kexhibit42.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Exhibit 4.2</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> to the Registrant&#8217;s Annual Report on </font><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/0001835830-24-000022-index.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">Form 1</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/0001835830-24-000022-index.htm" style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%;text-decoration:underline">0-K</a></font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%"> for the year ended December 31, 2023, filed with the Commission on February 29, 2024, including any amendments or reports filed for the purpose of updating such description.</font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">All documents subsequently filed by the Registrant pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the filing of a post-effective amendment to the Registration Statement which indicates that all of the shares registered hereunder have been sold or which deregisters all of such shares then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the respective dates of filing of such documents&#59; provided, however, that documents or information deemed to have been furnished and not filed in accordance with Commission rules shall not be deemed incorporated by reference into this Registration Statement. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein, or in any other subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such earlier statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.</font></div><div style="height:72pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">1</font></div></div></div><div id="if285563679054f6287edd9e6467fe6d6_25"></div><hr style="page-break-after:always"><div style="min-height:72pt;width:100%"><div style="text-indent:18pt"><font><br></font></div></div><div style="-sec-extract:summary;margin-bottom:9pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Item 8.&#160;&#160;&#160;&#160;</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;text-decoration:underline">Exhibits</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">.</font></div><div><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:98.717%"><tr><td style="width:1.0%"></td><td style="width:6.529%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:35.750%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:6.529%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:12.211%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:8.477%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:8.477%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.449%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:10.433%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="27" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Incorporated by Reference</font></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Exhibit Number</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Exhibit Title</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Form</font></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">File No.</font></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Exhibit</font></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Filing Date</font></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Filed Herewith</font></td></tr><tr><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">4.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/a10-kexhibit31.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Amended and Restated Certificate of Incorporation.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">10-K</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">001-41806</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2&#47;29&#47;24</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">4.2</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000183583024000022/a10-kexhibit32.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Amended and Restated Bylaws.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">10-K</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">001-41806</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3.2</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2&#47;29&#47;24</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">4.3</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Spe</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">c</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">imen</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"> Series A</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"> C</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">ommon </a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">S</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">tock </a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">C</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">ertificate of </a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Klaviyo, Inc</a><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023030618/exhibit41-sx1.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">S-1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">333-274211</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">4.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">8&#47;25&#47;23</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">5.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="s-8exhibit51.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Opinion of Goodwin Procter LLP.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">X</font></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">23.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="s-8exhibit231.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Consent of Deloitte &#38; Touche LLP, Independent Registered Public Accounting Firm.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">X</font></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">23.2</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="s-8exhibit51.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Consent of Goodwin Procter LLP (included in Exhibit 5.1).</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">X</font></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">24.1</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="#if285563679054f6287edd9e6467fe6d6_31" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Power of Attorney (contained on signature page hereto).</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">X</font></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">99.1#</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023031916/exhibit103-sx1a.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">2023 Stock Option and Incentive Plan, and forms of agreements thereunder.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">S-1&#47;A</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">333-274211</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">10.3</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">9&#47;11&#47;23</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">99.2#</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="https://www.sec.gov/Archives/edgar/data/1835830/000162828023031916/exhibit1014-sx1a.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">2023 Employee Stock Purchase Plan, and forms of agreements thereunder.</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">S-1&#47;A</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">333-274211</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">10.14</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">9&#47;11&#47;23</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">107</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:top"><div style="padding-left:0.02pt"><font style="color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline"><a href="s-8ex107xfilingfeetable.htm" style="-sec-extract:exhibit;color:#0000ff;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%;text-decoration:underline">Filing Fee Table</a></font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:middle"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">X</font></td></tr><tr style="height:14pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">#</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="27" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:top"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Indicates management contract or compensatory plan, contract or agreement.</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr></table></div><div style="height:72pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div style="-sec-extract:summary;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">2</font></div></div></div><div id="if285563679054f6287edd9e6467fe6d6_31"></div><hr style="page-break-after:always"><div style="min-height:36pt;width:100%"><div style="text-indent:18pt"><font><br></font></div></div><div style="margin-bottom:9pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">SIGNATURES</font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">Pursuant to the requirements of the Securities Act of 1933, as amended, 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 Boston, Massachusetts, on February 29, 2024.</font></div><div style="margin-bottom:9pt;text-align:right"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:37.179%"><tr><td style="width:1.0%"></td><td style="width:16.572%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:81.228%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">KLAVIYO, INC.</font></td></tr><tr style="height:8pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">By&#58;</font></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="margin-bottom:1.5pt;margin-top:2.65pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:139%">&#47;s&#47; </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:12pt;font-weight:400;line-height:139%"> </font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:139%">Andrew Bialecki</font></div></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Andrew Bialecki</font></td></tr><tr><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt 2px 1.02pt;text-align:left;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Chief Executive Officer</font></td></tr></table></div><div style="margin-bottom:9pt;text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">POWER OF ATTORNEY AND SIGNATURES</font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Andrew Bialecki, Amanda Whalen, and Landon Edmond, and each of them, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign the Registration Statement on Form S-8 of Klaviyo, Inc., and any or all amendments (including post-effective amendments), and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite or necessary to be done in connection therewith and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof. </font></div><div style="margin-bottom:9pt;text-align:justify;text-indent:18pt"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:112%">Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement on Form S-8 has been signed by the following persons in the capacities and on the dates indicated.</font></div><div><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:100.000%"><tr><td style="width:1.0%"></td><td style="width:29.508%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.441%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:39.284%"></td><td style="width:0.1%"></td><td style="width:0.1%"></td><td style="width:0.441%"></td><td style="width:0.1%"></td><td style="width:1.0%"></td><td style="width:26.626%"></td><td style="width:0.1%"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Signature</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Title</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Date</font></td></tr><tr style="height:3pt"><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="border-top:1pt solid #000;padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Andrew Bialecki</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">Chief Executive Officer and Director</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">(</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:110%">Principal Executive Officer</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">)</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Andrew Bialecki</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Amanda Whalen</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">Chief Financial Officer</font></div><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">(</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:110%">Principal Financial and Accounting Officer</font><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:110%">)</font></div></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Amanda Whalen</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Jennifer Ceran</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Jennifer Ceran</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Luciano Fernandez Gomez</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Luciano Fernandez Gomez</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Edward Hallen</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Chief Product Officer and Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Edward Hallen</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Ping Li</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Ping Li</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Michael Medici</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Michael Medici</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Roxanne Oulman</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Roxanne Oulman</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr style="height:3pt"><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">&#47;s&#47; Susan St. Ledger</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Director</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-align:center"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Susan St. Ledger</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" 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Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">February 29, 2024</font></div></td></tr><tr><td colspan="3" style="border-top:1pt solid #000;padding:2px 1pt;text-align:center;vertical-align:bottom"><font style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Tony Weisman</font></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td><td colspan="3" style="padding:0 1pt"></td></tr></table></div><div style="height:18pt;position:relative;width:100%"><div style="bottom:0;position:absolute;width:100%"><div><font><br></font></div></div></div></body></html>
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Document
As filed with the U.S. Securities and Exchange Commission on February 29, 2024
Registration No. 333-
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM S-8
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933
Klaviyo, Inc.
(Exact name of registrant as specified in its charter)
Delaware
(State or other jurisdiction of incorporation or organization)
46-0989964
(I.R.S. Employer Identification No.)
125 Summer Street, 6th Floor
Boston, MA 02110
(Address of Principal Executive Offices and Zip Code)
2023 Stock Option and Incentive Plan
2023 Employee Stock Purchase Plan
(Full titles of the plans)
Andrew Bialecki
Co-Founder, Chief Executive Officer
Klaviyo, Inc.
125 Summer Street, 6th Floor
Boston, MA 02110
(Name and address of agent for service)
(617) 213-1788
(Telephone number, including area code, of agent for service)
Copies to:
Craig M. Schmitz
Bradley C. Weber
Kim S. de Glossop
Kristin A. Gerber
Goodwin Procter LLP
100 Northern Avenue
Boston, MA 02210
(617) 570-1000
Landon R. Edmond
Cameron S. Vermette
Klaviyo, Inc.
125 Summer Street, 6th Floor
Boston, MA 02110
(617) 213-1788
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.
Large accelerated filer
☐
Accelerated filer
☐
Non-accelerated filer
ý
Smaller reporting company
☐
Emerging growth company
ý
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐
EXPLANATORY NOTE
Klaviyo, Inc. (the "Registrant") is filing this Registration Statement on Form S-8 (the "Registration Statement") with the Securities and Exchange Commission (the "Commission") to register (i)
12,968,292
additional shares of its Series A Common Stock, par value $0.001 per share (the "Series A common stock"), under the 2023 Stock Option and Incentive Plan (the "2023 Plan") and (ii)
2,593,658
additional shares of its Series A common stock under the 2023 Employee Stock Purchase Plan (the "2023 ESPP"), pursuant to the provisions of the 2023 Plan and 2023 ESPP, respectively, which provide for an automatic increase in the number of shares reserved and available for issuance under such plans on January 1, 2024,
and each January 1 thereafter until each of the plans terminate respective to their terms
.
This Registration Statement registers additional securities of the same class as other securities of the Registrant for which a Registration Statement on
Form S-8
filed with the Commission on September 19, 2023
(File No. 333-
274591
) is effective.
Pursuant to General Instruction E of Form S-8, the contents of the Registration Statement referenced above are hereby incorporated by reference in this Registration Statement to the extent not replaced hereby.
PART II
INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
Item 3.
Incorporation of Documents by Reference
.
The following documents filed with the Commission by the Registrant are incorporated by reference into this Registration Statement:
(a)
The contents of the Registration Statement on
Form S-8
filed with the Commission on September 19, 2023 (File No. 333-274591);
(b)
The Registrant's Annual Report on
Form 10-K
for the year ended December 31, 2023, filed with the Commission on February 29, 2024;
(c)
All other reports filed by the Registrant pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), since December 31, 2023; and
(d)
The description of the Registrant's Series A common stock contained in the Registrant's Registration Statement on
Form 8-A
(File No. 001-41806) filed with the Commission on September 15, 2023 under Section 12(b) of the Exchange Act, updated by
Exhibit 4.2
to the Registrant's Annual Report on
Form 1
0-K
for the year ended December 31, 2023, filed with the Commission on February 29, 2024, including any amendments or reports filed for the purpose of updating such description.
All documents subsequently filed by the Registrant pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the filing of a post-effective amendment to the Registration Statement which indicates that all of the shares registered hereunder have been sold or which deregisters all of such shares then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the respective dates of filing of such documents; provided, however, that documents or information deemed to have been furnished and not filed in accordance with Commission rules shall not be deemed incorporated by reference into this Registration Statement. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein, or in any other subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such earlier statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.
1
Item 8.
Exhibits
.
Incorporated by Reference
Exhibit Number
Exhibit Title
Form
File No.
Exhibit
Filing Date
Filed Herewith
4.1
Amended and Restated Certificate of Incorporation.
10-K
001-41806
3.1
2/29/24
4.2
Amended and Restated Bylaws.
10-K
001-41806
3.2
2/29/24
4.3
Spe
c
imen
Series A
C
ommon
S
tock
C
ertificate of
Klaviyo, Inc
.
S-1
333-274211
4.1
8/25/23
5.1
Opinion of Goodwin Procter LLP.
X
23.1
Consent of Deloitte & Touche LLP, Independent Registered Public Accounting Firm.
X
23.2
Consent of Goodwin Procter LLP (included in Exhibit 5.1).
X
24.1
Power of Attorney (contained on signature page hereto).
X
99.1#
2023 Stock Option and Incentive Plan, and forms of agreements thereunder.
S-1/A
333-274211
10.3
9/11/23
99.2#
2023 Employee Stock Purchase Plan, and forms of agreements thereunder.
S-1/A
333-274211
10.14
9/11/23
107
Filing Fee Table
X
#
Indicates management contract or compensatory plan, contract or agreement.
2
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, as amended, 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 Boston, Massachusetts, on February 29, 2024.
KLAVIYO, INC.
By:
/s/
Andrew Bialecki
Andrew Bialecki
Chief Executive Officer
POWER OF ATTORNEY AND SIGNATURES
KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Andrew Bialecki, Amanda Whalen, and Landon Edmond, and each of them, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign the Registration Statement on Form S-8 of Klaviyo, Inc., and any or all amendments (including post-effective amendments), and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite or necessary to be done in connection therewith and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.
Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement on Form S-8 has been signed by the following persons in the capacities and on the dates indicated.
Signature
Title
Date
/s/ Andrew Bialecki
Chief Executive Officer and Director
(
Principal Executive Officer
)
February 29, 2024
Andrew Bialecki
/s/ Amanda Whalen
Chief Financial Officer
(
Principal Financial and Accounting Officer
)
February 29, 2024
Amanda Whalen
/s/ Jennifer Ceran
Director
February 29, 2024
Jennifer Ceran
/s/ Luciano Fernandez Gomez
Director
February 29, 2024
Luciano Fernandez Gomez
/s/ Edward Hallen
Chief Product Officer and Director
February 29, 2024
Edward Hallen
/s/ Ping Li
Director
February 29, 2024
Ping Li
/s/ Michael Medici
Director
February 29, 2024
Michael Medici
/s/ Roxanne Oulman
Director
February 29, 2024
Roxanne Oulman
/s/ Susan St. Ledger
Director
February 29, 2024
Susan St. Ledger
/s/ Tony Weisman
Director
February 29, 2024
Tony Weisman