26 U.S.C. § 7272: Penalty for failure to register or reregister

(a) In generalAny person (other than persons required to register under subtitle E, or persons engaging in a trade or business on which a special tax is imposed by such subtitle) who fails to register with the Secretary as required by this title or by regulations issued thereunder shall be liable to a penalty of $50 ($10,000 in the case of a failure to register or reregister under section 4101). (b) Cross referencesFor provisions relating to persons required by this title to register, see sections 4101, 4412, and 7011.