27 CFR 71.45: Basic permits.

Whenever the appropriate TTB officer has reason to believe that any person has willfully violated any of the conditions of his basic permit, or has not in fact or in good faith engaged in the operations authorized by such permit for a period of more than two years, or that such permit was procured through fraud, misrepresentation or concealment of material facts, he shall issue a citation for the suspension, revocation or annulment of such permit, as the case may be.