27 CFR 447.34: Maintenance of records by persons required to register as importers of Import List articles.

(a) Registrants under this part engaged in the business of importing articles subject to controls under 27 CFR Parts 478 and 479 shall maintain records in accordance with the applicable provisions of those parts.

(b) Registrants under this part engaged in importing articles on the U.S. Munitions Import List subject to the permit procedures of subpart E of this part must maintain for a period of 6 years records bearing on such articles imported, including records concerning their acquisition and disposition, including Forms 6 and 6A. The appropriate ATF officer may prescribe a longer or shorter period in individual cases as such officer deems necessary. See § 478.129 of this chapter for articles subject to import control under part 478 of this chapter.