D.C. Mun. Regs. tit. 16, r. 16-806
Each individual licensed as a contractor; the officers or members of any firm, partnership, joint stock company, corporation, association, or incorporated society licensed as a contractor; and each salesperson employed by a contractor shall, while engaging, away from the premises for which the license is issued, in any dealings with a homeowner in connection with carrying on the home improvement business with which that contractor, officer, member, or salesperson is associated, carry on his or her person an identification card issued to him or her by the Director.
Upon the request of a homeowner or other person with whom the contractor or salesperson may deal in connection with licensed activities, each person required by this section to carry an identification card as a contractor or salesperson shall display the card and shall furnish the homeowner or other person dealing with the contractor or salesperson a business card or other written matter containing the full name of the contractor or salesperson and the contractor's or salesperson's license number, as the case may be, including, in the case of the salesperson, the name of the contractor by whom he or she is employed.
Each person issued an identification card by the Director shall, upon terminating his or her association with the contractor whose name appears on the card, surrender the card to the Director within five (5) business days after the termination of such association.
Each licensed contractor shall, within five (5) business days from the date of termination of an employee to whom an identification card was issued, notify the Director of the termination of any association between the contractor and that person.
D.C. Mun. Regs. tit. 16, r. 16-806