21 CFR 1312.16 - Cancellation of permit; expiration date.
(a) A permit may be canceled after being issued, at the request of the importer, provided no shipment has been made thereunder. In the event that a permit is lost, the Administrator may, upon the production by the importer of satisfactory proof, by affidavit or otherwise, issue a duplicate permit. Nothing in this part shall affect the right, hereby reserved by the Administrator, to cancel a permit at any time for proper cause.
(b) An import permit shall not be valid after the date specified therein, and in no event shall the date be subsequent to 6 months after the date the permit is issued. Any unused import permit shall be returned for cancellation by the registrant to the Import/Export Unit, Drug Enforcement Administration. See the Table of DEA Mailing Addresses in § 1321.01 of this chapter for the current mailing address.