# EDGAR Filing Document

**Accession Number:** 0001835830
**File Stem:** 0001470831-26-000380
**Filing Date:** 2026-4
**Character Count:** 9369
**Document Hash:** b2b78d8cdcfbeb8afe6928a094ce708f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001470831-26-000380.hdr.sgml**: 20260417

**ACCESSION NUMBER**: 0001470831-26-000380

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260415

**FILED AS OF DATE**: 20260417

**DATE AS OF CHANGE**: 20260417

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Whalen Amanda
- **CENTRAL INDEX KEY:** 0001991131

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41806
- **FILM NUMBER:** 26873067

**MAIL ADDRESS:**
- **STREET 1:** KLAVIYO, INC.
- **STREET 2:** 125 SUMMER STREET, 6TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02110
**ISSUER**: 

**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

**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

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[x] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Whalen Amanda<br><sub>(Last) (First) (Middle)</sub><br>C/O KLAVIYO, INC.<br>125 SUMMER STREET, 6TH FLOOR<br><sub>(Street)</sub><br>BOSTON, MA 02110<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-15 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Chief Financial Officer_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Klaviyo, Inc. [ KVYO ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Series A Common Stock | 2026-04-15 |  | A |  | 265151<sup>(1)</sup> | A | $0 | 677576 | D |  |
| Series A Common Stock | 2026-04-15 |  | A |  | 227272<sup>(2)(3)</sup> | A | $0 | 904848 | D |  |
| Series A Common Stock | 2026-04-16 |  | C<sup>(4)</sup> |  | 4293 | A | <sup>(5)</sup> | 909141 | D |  |
| Series A Common Stock | 2026-04-16 |  | S<sup>(4)</sup> |  | 14000 | D | 18.54<sup>(6)</sup> | 895141<sup>(7)</sup> | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Series B Common Stock | <sup>(5)</sup> | 2026-04-16 |  | C<sup>(4)</sup> |  |  | 4293 | <sup>(5)</sup> | <sup>(5)</sup> | Series A Common Stock | 4293 | $0 | 297112<sup>(8)</sup> | D |  |

---

### Footnotes:

(1) Represents restricted stock units ("RSUs") awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), upon vesting and settlement. The RSUs vest as follows: (i) 50% of the RSUs will vest in eight equal quarterly installments, with the first such installment vesting on May 15, 2026, and (ii) thereafter the remaining 50% of the RSUs will vest in four equal quarterly installments, subject to the Reporting Person's continued service on each such vesting date.

(2) Represents performance stock units ("PSUs") awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement. The PSUs will vest in up to three tranches over a two-year measurement period, subject to the achievement of specified performance targets tied to the trading price of the Series A Common Stock and the Reporting Person's continued service in the same or substantially equivalent position as the Reporting Person held as of the grant date through the applicable vesting date. Each tranche of PSUs will vest only if the average closing price of the Series A Common Stock for a period of at least sixty consecutive calendar days is at or above a specified dollar value during the applicable measurement period.

(3) (continued) The stock price targets for tranches 1 through 3 are $30.00, $50.00, and $75.00 per share, respectively, subject to proportionate adjustment in the event of any stock split or other similar change in the Issuer's capital stock.

(4) These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

(5) Each share of the Issuer's Series B Common Stock, par value $0.001 per share ("Series B Common Stock"), is convertible at any time at the option of the holder into one share of Series A Common Stock, and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date.

(6) The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.34 to $18.98 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

(7) Consists of (i) 42,687 shares of Series A Common Stock; (ii) 625,182 unvested RSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested PSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

(8) Consists of (i) 262,737 shares of Series B Common Stock and (ii) 34,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

**Signature:** /s/ Landon Edmond, Attorney-in-Fact  
**Date:** 2026-04-17

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**