27 C.F.R. § 19.119

If the proprietor intends to extend or curtail any part of the plant premises, except under alternate operations that are covered by §§ 19.142 and 19.143, the proprietor must file form TTB F 5110.41, Registration of Distilled Spirits Plant, to amend the registration. The proprietor must not extend or curtail any premises or equipment before the amended registration is approved.