D.C. Mun. Regs. tit. 17, § 220
220.1 If a license is lost, destroyed, or defaced, the licensee shall present to the Director a properly notarized statement to that effect.
220.2 A duplicate license shall be issued upon payment of a fee of three dollars ($3), except that where this fee is greater than the license fee, the license fee will be charged.
220.3 Refunds shall be given as follows:
(a) A business license fee, less five dollars ($5), will be refunded if the applicant has failed to qualify for a license;
(b) Occupational license refunds shall be made only on application of an applicant for a license who has not received a license and on a certificate of the Director that the applicant has failed to pass the required examination as follows:
(1) One examination - original fee less four dollars ($4); or
(2) Two examinations - original fee less six dollars ($6);
(c) Any fees erroneously collected by the District of Columbia for a license under this chapter shall be refunded.
SOURCE: 5J DCRR §§724 and 725.