X0306 4 2018-11-15 0001447669 TWILIO INC TWLO 0001665730 Smith Karyn C/O TWILIO INC. 375 BEALE STREET, SUITE 300 SAN FRANCISCO CA 94105 1 General Counsel and Secretary Class A Common Stock 2018-11-15 4 S 0 1939 82.42 D 44646 D Class A Common Stock 2018-11-15 4 S 0 26 84.1021 D 44620 D Class A Common Stock 2018-11-15 5 G 0 E 1922 0 D 42698 D Class A Common Stock 2018-11-15 5 G 0 E 1922 0 A 3792 I By The Karyn Smith Revocable Trust Represents the number of shares sold to cover the statutory tax withholding obligations in connection with the vesting of Restricted Stock Units ("RSUs"). This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of minimum statutory tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary sale by the Reporting Person. A portion of these shares represent RSUs. Each RSU represents the contingent right to receive one share of the Issuer's Class A common stock. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $84.0754 to $84.1288 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to 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. Represents shares that were contributed by the Reporting Person to the Reporting Person's trust. Represents the shares received by the Reporting Person's trust. The Karyn Smith Revocable Trust U/A/D 9/15/06 Amended 12/23/11, Karyn Smith Trustee. /s/ Alexis Rhorer as attorney in fact for Reporting Person 2018-11-19