27 C.F.R. § 70.184
(b) Return to owner. If the owner of the property can be readily found, the appropriate TTB officer shall give the owner written notice of the appropriate TTB officer's determination of the appraised value of the property. However, if the appropriate TTB officer determines that the circumstances require immediate action, the appropriate TTB officer may give the owner an oral notice of the determination of the appraised value of the property, which notice shall be confirmed in writing prior to sale. The property shall be returned to the owner if, within the time specified in the notice, the owner:
(c) Immediate sale. If the owner does not pay the amount of the appraised value of the seized property within the time specified in the notice, or furnish bond as provided in paragraph (b) of this section within such time, the appropriate TTB officer shall as soon as practicable make public sale of the property in accordance with the following terms and conditions:
(3) Terms. The purchase price shall be paid in full upon acceptance of the highest bid. The payment shall be made by cash, or by a certified, cashier's or treasurer's check drawn on any bank or trust company incorporated under the laws of the United States or under the laws of any State, Territory, or possession of the United States, or by a U.S. postal, bank, express, or telegraph money order.
(26 U.S.C. 6336)