27 CFR §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—

(1) A request to cancel the permit,

(2) A statement of the disposition made, as provided in § 22.154, of all tax-free and recovered alcohol, and

(3) The date of discontinuance.