(A) The provisions of this chapter shall not apply to any person transacting and carrying on any business exempt by virtue of the United States Constitution or State Constitution or applicable laws of the United States or of the state from the payment of the taxes provided for in this chapter.
(B) Any person claiming an exemption pursuant to the provisions of this section shall file a sworn statement with the Collector stating the facts upon which an exemption is claimed. The Collector, upon a proper showing contained in the sworn statement, shall issue a license to such person claiming such exemption without payment to the city of the license tax required by the provisions of this chapter. In the absence of such statement substantiating the claim the person shall be liable for the payment of the taxes imposed by the provisions of this chapter.
(C) The Collector, after giving written notice and a reasonable opportunity for a hearing to a licensee, may revoke any license granted pursuant to the provisions of this section upon receipt of credible and competent information that the licensee is not entitled to the claimed exemption.
(`78 Code, § 5.02.250.)