D.C. Mun. Regs. tit. 17, r. 17-305
A license as a Refrigeration and Air Conditioning Contractor may be issued to a person, firm, or corporation proposing to engage in that business if the following requirements are met:
If the highest grade of license held by the person conducting or regularly employed in the business of the Refrigeration and Air Conditioning Contractor is that of Master Refrigeration and Air Conditioning Mechanic Limited, the license issued to that contractor shall be limited to the installation, maintenance, repair, or replacement of refrigeration or air conditioning systems up to and including twenty-five (25) compressor horsepower or the equivalent tons of refrigeration in the aggregate.
The license issued to a Refrigeration and Air Conditioning Contractor shall be valid only so long as the business of the licensee is conducted by or regularly employs at least one (1) person holding a valid license as a Master Refrigeration and Air Conditioning Mechanic or Master Refrigeration and Air Conditioning Mechanic Limited.
At least one (1) master mechanic conducting or regularly employed in the business of the Refrigeration and Air Conditioning Contractor shall be named the "designated master mechanic" for that contractor. The designated master mechanic shall supervise and be responsible for the work to be performed under the authority of the permits issued to the contractor in the name of the designated master.
For the purposes of this section, the term "regularly employs" or "regularly employed" means that the Master Refrigeration and Air Conditioning Mechanic or Master Refrigeration and Air Conditioning Mechanic Limited shall be available to supervise the installation of refrigeration or air conditioning equipment at all times during the installation, whenever such work is being performed by any mechanic under his or her supervision and for whose work he or she is responsible.
The non-availability of the Master Refrigeration and Air Conditioning Mechanic or Master Refrigeration and Air Conditioning Mechanic Limited designated under § 305.4 to supervise the performance of any refrigeration or air conditioning work performed under the authority of a permit issued to that master shall be cause for the suspension or revocation of the license of that designated master mechanic.
If the master or limited master mechanic severs his or her connection with the contractor, both the master or limited master and the contractor shall notify the Director promptly.
If a contractor is a non-resident of the District of Columbia, or has designated on the license application a local officer of the firm or corporation who is a non-resident of the District, the contractor shall also designate by name and address an individual who is a resident of the District, and who, by a signed statement, agrees to be the local agent of the contractor to accept notices, summons, or other legal notices for that contractor and to notify the Director of any change in the agent's address or any change in the conditions of the agreement to act as agent for the contractor.
The issuance and continuing validity of a contractor's license shall be conditioned on the contractor's furnishing and keeping in force a bond in the form required by this chapter.
A contractor with more than one (1) business location shall obtain a separate license and file a separate bond for each business location.
D.C. Mun. Regs. tit. 17, r. 17-305