I think I found my answer here: 21.3.4 Field Assistance | Internal Revenue Service (irs.gov)
and ok with it sent payable to "internal revenue service"
21.3.4.7.5 (03-22-2019)
Verifying payment information. All payee lines must be over-stamped with "United States Treasury" except for the following:
US Treasury
U.S. Treasury
United States Treasury - Note: The abbreviation "Treas" is acceptable when used in conjunction with "United States" or "U.S."
Internal Revenue Service
Department of Treasury
Department of the Treasury - Note: The abbreviation "Dept" is acceptable when used in conjunction with "Treasury" .
