Section 102-118.630 - How must a TSP refund amounts due to GSA?(a) TSPs must promptly refund amounts due to GSA, preferably by EFT. If an EFT is not used, checks must be made payable to "General Services Administration", including the document reference number, TSP name, bill number(s), taxpayer identification number and standard carrier alpha code, then mailed to: General Services Administration, Government Lock Box 9006, 1005 Convention Plaza, St. Louis, MO 63101.(b) If an EFT address is needed, please contact the GSA Transportation Audits Division at: General Services Administration, Office of Travel, Employee Relocation and Transportation, Attn: Transportation Audits Division, 1800 F Street NW, 3rd Floor, Mail Hub 3400, Washington, DC 20405; or via email to audits.policy@gsa.gov. 87 FR 32326 , May 31, 2022 Note 1 to § 102-118.630: Amounts collected by GSA are returned to the Treasurer of the United States (31 U.S.C. 3726 ).