27 CFR § 19.126 - General rules for amending an operating permit.
(a) When and how to amend. If there is a change in any of the information that the proprietor provided as part of the current approved application for an operating permit, the proprietor must amend the operating permit by submitting written documentation in accordance with this section to the appropriate TTB officer in writing within 30 days of the change unless another time period is specified in this subpart.
(1) TTB F 5110.25. Except when a letterhead application or letterhead notice procedure is allowed under this subpart, the proprietor must amend the operating permit by submitting an amended form TTB F 5110.25, Application for Operating Permit Under 26 U.S.C. 5171(d). If the changes only affect parts or pages of the application for an operating permit the proprietor only needs to submit the necessary pages or information that will make the permit file current.
(2) Letterhead applications. For certain changes specified in this subpart, the proprietor may submit a letterhead application instead of an amended TTB F 5110.25. The letterhead application must identify the distilled spirits plant for which the application applies. The letterhead application change is subject to TTB approval. The appropriate TTB officer may, at any time, require that the proprietor submit an amended application on TTB F 5110.25 if administrative difficulties occur as a result of the letterhead application.
(3) Letterhead notices. For certain changes noted in this subpart only a letterhead notice is required. A letterhead notice does not require approval by TTB. The appropriate TTB officer may, at any time, require that the proprietor submit amended application on TTB F 5110.25 if administrative difficulties occur as a result of the letterhead notice.
(b) FAA Act permits. If there are changes that affect a basic permit issued under the Federal Alcohol Administration Act, the proprietor must amend the basic permit in accordance with the procedures set forth in part 1 of this chapter.