27 C.F.R. § 31.181 – Requirements for retail dealers.

(a) Records of receipt. All retail dealers must keep at their place of business complete records showing the quantities of all distilled spirits, wines, and beer received, from whom the distilled spirits, wines, and beer were received, and the dates of receipt. However, the appropriate TTB officer may, upon request, authorize the maintenance of records at another business premises also under the control of the same retail dealer when it is determined that such maintenance will not cause undue inconvenience to TTB officers desiring to examine those records. Records of receipts shall consist of all purchase invoices or bills covering distilled spirits, wines, and beer received, or, at the option of the retail dealer, a book record containing all of the required information.
(b) Records of sales of 20 wine gallons (75.7 liters) or more. Every retail dealer who makes sales of distilled spirits, of wines, or of beer in quantities of 20 wine gallons (75.7 liters) or more to the same person at the same time must prepare and keep a record of each sale. The record must show the date of sale, the name and address of the purchaser, the kind and quantity of each kind of liquors sold, and the serial numbers of all full cases of distilled spirits included in the sale. Each entry on that record must be supported by a corresponding delivery receipt (which may be executed on a copy of the sales slip) signed by the purchaser or the purchaser's agent.
(26 U.S.C. 5122, 5123)
(Approved by the Office of Management and Budget under control number 1513-0066)