0001959173-25-007029.txt : 20251117 0001959173-25-007029.hdr.sgml : 20251117 20251117100958 ACCESSION NUMBER: 0001959173-25-007029 CONFORMED SUBMISSION TYPE: 144 PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20251117 DATE AS OF CHANGE: 20251117 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: Klaviyo, Inc. CENTRAL INDEX KEY: 0001835830 STANDARD INDUSTRIAL CLASSIFICATION: SERVICES-PREPACKAGED SOFTWARE [7372] ORGANIZATION NAME: 06 Technology EIN: 000000000 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: 144 SEC ACT: 1933 Act SEC FILE NUMBER: 001-41806 FILM NUMBER: 251489673 BUSINESS ADDRESS: STREET 1: 125 SUMMER STREET, FLOOR 6 CITY: BOSTON STATE: MA ZIP: 02110 BUSINESS PHONE: 800-338-1744 MAIL ADDRESS: STREET 1: 125 SUMMER STREET, FLOOR 6 CITY: BOSTON STATE: MA ZIP: 02110 REPORTING-OWNER: COMPANY DATA: COMPANY CONFORMED NAME: Galvin Carmel CENTRAL INDEX KEY: 0001733091 ORGANIZATION NAME: FILING VALUES: FORM TYPE: 144 MAIL ADDRESS: STREET 1: 111 MCINNIS PARKWAY CITY: SAN RAFAEL STATE: CA ZIP: 94903 144 1 primary_doc.xml 144 0001733091 XXXXXXXX LIVE 0001835830 Klaviyo, Inc. 001-41806 125 SUMMER STREET, FLOOR 6 BOSTON MA 02110 800-338-1744 Galvin Carmel Officer Series A Fidelity Brokerage Services LLC

900 Salem Street Smithfield RI 02917

11156 319284.72 137856147 11/17/2025 NYSE Series A 11/14/2025 Restricted Stock Vesting Issuer N 11156 11/14/2025 Compensation N Carmel Galvin

125 Summer Street 6th Floor Boston MA 02110

Series A 08/18/2025 11155 353264.99 11/17/2025 11/26/2024 /s/ Jennifer Ruchti, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Carmel Galvin