Section 29.203 - Other Federal tax exemptions(a) Pursuant to 26 U.S.C. 4293 , the Secretary of the Treasury has exempted the United States from the communications excise tax imposed in 26 U.S.C. 4251 , when the supplies and services are for the exclusive use of the United States. (Secretarial Authorization, June 20, 1947, Internal Revenue Cumulative Bulletin, 1947-1, 205.)(b) Pursuant to 26 U.S.C. 4483(b) , the Secretary of the Treasury has exempted the United States from the federal highway vehicle users tax imposed in 26 U.S.C. 4481 . The exemption applies whether the vehicle is owned or leased by the United States. (Secretarial Authorization, Internal Revenue Cumulative Bulletin, 1956-2, 1369.)