X0306 4 2021-05-11 0 0001508655 Sixth Street Specialty Lending, Inc. TSLX 0001240367 HIGGINBOTHAM RICHARD A C/O SIXTH STREET SPECIALTY LENDING, INC. 2100 MCKINNEY AVENUE, SUITE 1500 DALLAS TX 75201 1 0 0 0 Common Stock 2021-05-11 4 P 0 5000 21.8849 A 5000 I See Explanation of Responses Common Stock 2000 I See Explanation of Responses Common Stock 20000 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $21.85 to $21.92 inclusive. The reporting person undertakes to provide to Sixth Street Specialty Lending, Inc. (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 purchased at each separate price within the range set forth above. Shares held through a trust for which a member of Mr. Higginbotham's immediate family sharing the same household is the trustee. Mr. Higginbotham disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Higginbotham is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. Shares purchased for the account of a family member, over which Mr. Higginbotham has investment discretion. 4. Ian Simmonds is signing on behalf of Richard Higginbotham pursuant to a Power of Attorney dated January 4, 2021, which is attached hereto as an exhibit. /s/ Ian Simmonds, on behalf of Richard Higginbotham(4) 2021-05-13