27 C.F.R. § 22.68
A permittee who permanently discontinues the use of tax-free alcohol shall file a written notice with the appropriate TTB officer to cover the discontinuance. The notice will be accompanied by the permit, and contain—
(3) The date of discontinuance.
(Approved by the Office of Management and Budget under control number 1512-0335)
[T.D. ATF-199, 50 FR 9183, Mar. 6, 1985, as amended by T.D. ATF-443, 66 FR 13015, Mar. 2, 2001]