27 C.F.R. § 19.518 Imported spirits.
Title 27 - Alcohol, Tobacco Products and Firearms
When spirits which have been imported for nonbeverage purposes and transferred to bonded premises pursuant to 26 U.S.C. 5232 are withdrawn for beverage purposes, there shall be paid, in addition to the internal revenue tax imposed by 26 U.S.C. 5001, a tax equal to the duty which would have been paid had the spirits been imported for beverage purposes, less the duty already paid thereon. The additional tax shall be referred to as “additional tax—less duty”, and shall be paid at the time and in the manner that the basic tax is paid. The total quantity in proof gallons withdrawn shall be the basis of computing the tax at the rates indicated. The amount of the “additional tax—less duty” shall be stated separately and identified as such on the tax return. (Sec. 201, Pub. L. 85–859, 72 Stat. 1314, as amended (26 U.S.C. 5001))
Title 27: Alcohol, Tobacco and Firearms
PART 19—DISTILLED SPIRITS PLANTS
Subpart P—Transfer and Withdrawals
Withdrawals on Determination and Payment of Tax
§ 19.518 Imported spirits.

