D.C. Code § 47-2853.218
Tour guides.
(a) No person shall, for hire, guide or escort any person through or about the District of Columbia, or any part of the District, without first obtaining:
(1) A entertainment services license issued pursuant to § 47-2851.03 ;
(2) An occupational license for a tour guide issued by the Department of Licensing and Consumer Protection; and
(3) Approval from the Chief of Police.
(b) The Department may, through the promulgation of rules pursuant to Subchapter 1 of Chapter 5 of Title 2 , establish qualifications and fees for occupational licenses issued pursuant to this section, and establish civil penalties for violations of this section.