D.C. Mun. Regs. tit. 31, r. 31-1329
A taximeter business owner shall only sell and install taximeters for use in a District of Columbia licensed taxicab that have been approved by the Commission.
A taximeter business owner shall not sell a taximeter for use in a taxicab licensed by the Commission unless a valid vehicle license from the Commission is presented.
A taximeter business owner shall not sell a taximeter for use in a Commission licensed vehicle unless the installation, testing and certification of the taximeter/vehicle assembly is performed by the taximeter business licensee or an employee thereof.
A taximeter business owner shall report to the Commission, within seven (7) days, all sales, trades or exchanges of taximeters by the licensed taximeter business on a form prescribed by the Commission.
A taximeter business owner shall inform all purchasers in writing, before the sale takes place, of any and all restrictions imposed by the taximeter manufacturer and/or taximeter business licensee regarding the testing, repairs, calibration and installation of the taximeter.
A taximeter business owner shall remove, deface, or otherwise void the validity of the certification sticker upon receipt of a taximeter purchased, exchanged, or accepted in trade by the taximeter business licensee, and report such decertification to the Commission.
The certification sticker must conform to all specifications established by the Commission and bear the name of the Chairperson of the Commission.
All installations of taximeters in taxicabs license to operate in the District of Columbia must be in accordance with specifications which have been filed with and approved by the Commission.
No change in the method of installation shall be made unless the installation method has been filed with and approved by the Commission.
D.C. Mun. Regs. tit. 31, r. 31-1329