27 C.F.R. § 19.372 – Physical inventories of bottled and packaged spirits.

(a) Physical inventories. Generally, a proprietor must take physical inventories of bottled and packaged spirits in the processing account for the return periods ending June 30 and December 31, and at any other time that the appropriate TTB officer requires. Physical inventories may be taken within a period of a few days before or after June 30 or December 31 if:
1. (1) The period does not include more than one complete weekend; and
2. (2) Necessary adjustments are made to the inventory record to reflect the actual quantities on hand June 30 or December 31.
(b) Alternate dates. On approval of an application filed with the appropriate TTB officer, required physical inventories may be taken on dates other than June 30 and December 31 if the dates established for taking such inventories:
1. (1) Coincide with the end of a return period, and
2. (2) Are approximately 6 months apart.
(c) Waiver of physical inventory. A proprietor may file an application to take only one physical inventory per year. The appropriate TTB officer may approve the application if she or he finds that only one physical inventory per year will be sufficient to protect the revenue. However, the requirement for the waived inventory may be reimposed if it becomes necessary for protection of the revenue.
(d) Notification of physical inventory. A proprietor must notify the appropriate TTB officer at least 5 business days in advance of the date and time of a physical inventory of bottled or packaged spirits. TTB officers may be assigned to verify or supervise physical inventories taken under the provisions of this section.
(26 U.S.C. 5201)