27 C.F.R. § 46.6

Any person who, having paid the tax with respect to an article, desires to claim refund or credit of any amount of such tax to which the provisions of this subpart are applicable must:

(a) File a claim, as provided in § 46.7,

(b) Comply with any other provisions of law or regulations which may apply to the claim, and

(c) If, at the time of filing the claim, neither he nor the owner has sold or contracted to sell the articles involved in the claim, file a bond on TTB Form 5620.10, as provided by § 46.10.