26 C.F.R. § 601.522
Except as otherwise provided in this section, a power of attorney, or copy thereof, will be required for a representative of a principal (a) to perform the acts specified in paragraph (c)(1) of § 601.502 ; or (b) to sign any application, bond, notice, return, report, or other document required by, or provided for in, regulations issued pursuant to chapter 51 (Distilled Spirits, Wines, and Beer), Chapter 52 (Cigars, Cigarettes, and Cigarette Papers and Tubes), and chapter 53 (Machine Guns, Destructive Devices, and Certain Other Firearms), Internal Revenue Code, title 1 of the Gun Control Act of 1968, or the Federal Alcohol Administration Act, which is filed with or acted on by (1) the office of a regional regulatory administrator in the Bureau of Alcohol, Tobacco, and Firearms, or (2) the Director, Bureau of Alcohol, Tobacco, and Firearms. The power of attorney may be executed on Form 1534, copies of which may be obtained from the regional regulatory administrator in the Bureau of Alcohol, Tobacco, and Firearms. A power of attorney will not be required for a person authorized to sign on behalf of the principal by articles of incorporation, bylaws, or a board of directors, where an acceptable copy of such authorization is on file in the office of the regional regulatory administrator or of the Director. A power of attorney filed under the provisions of this section may cover one or more acts for which a power of attorney is required and will continue in effect with respect to such acts until revoked as provided in § 601.526 . The exceptions to the requirements for a power of attorney contained in paragraph (c) (3) and (4) of § 601.502 are applicable to powers of attorney under this section.
26 C.F.R. §601.522