Certain Series B Common Stock of Klaviyo, Inc. are subject to a Lock-Up Agreement Ending on 18-MAR-2024. These Series B Common Stock will be under lockup for 181 days starting from 19-SEP-2023 to 18-MAR-2024.

Details:
Officers, directors, and holders of substantially all of our Series A common stock, including the selling stockholders, have agreed with the underwriters, subject to certain exceptions, not to dispose of or hedge any of their shares of our Series A common stock or securities convertible into or exchangeable for shares of our Series A common stock during the period from the date of this prospectus continuing through the date 180 days after the date of this prospectus.