(a) The proprietor must submit a letterhead notice before making any material change in the construction or use of buildings or equipment at the plant other than changes covered by § 19.119, § 19.142 or § 19.143. The proprietor must:

1. (1) Describe the proposed change in detail;
2. (2) Keep a copy of the letterhead notice on file with the current notice of registration; and
3. (3) Incorporate the change in the next amendment to the registration submitted on form TTB F 5110.41, Registration of Distilled Spirits Plant, unless the appropriate TTB officer requires immediate submission of an amended TTB F 5110.41.

(b) The proprietor may make emergency changes in construction or use of buildings and equipment without prior letterhead notice. However, the proprietor must promptly report any emergency change to the appropriate TTB officer.

(26 U.S.C. 5172)