26 CFR 48.4222(c)-1: (c)-1 Revocation or suspension of registration.

The district director or the Director of International Operations, as the case may be, is authorized to revoke or temporarily suspend, upon written notice, the registration of any person and the right of such person to sell or purchase articles tax free under section 4221 of the Code in any case in which he finds that (1) the registrant is not a bona fide manufacturer, or a purchaser reselling direct to manufacturers or exporters; (2) the registrant is for some other reason not eligible under these regulations to retain a Certificate of Registry; (3) the registrant has used his registration to avoid the payment of any tax imposed by Chapter 32 of the Code, or to postpone or interfere in any manner with the collection of such tax; (4) such revocation or suspension is necessary to protect the revenue; or (5) the registrant failed to comply with the requirements of paragraph (c) of § 48.4222 (a)-1, relating to the evidence required to support a tax-free sale. The revocation or suspension of registration is in addition to any other penalty that may apply under the law for any act or failure to act.