Businesses with nexus in Washington D.C. are required to register with the District of Columbia Office of Tax and Revenue and to charge, collect, and remit the appropriate tax.

A business has nexus in the District of Columbia when it has a physical presence there, such as a retail store, warehouse, inventory, or the regular presence of traveling salespeople or representatives. However, out-of-state sellers can also establish nexus in the ways described below.

Washington D.C. nexus for out-of-district sellers

Affiliate nexus

Ties to businesses in Washington D.C., including affiliates, may create nexus for an out-of-state seller. The District considers an out-of-state vendor to be “engaging in business in the District” if the vendor does both the following:

• Maintains, occupies or uses, permanently or temporarily, directly or indirectly, or through a subsidiary or agent, by whatever name called, any office, place of distribution, sales or sample room or place, warehouse or storage place, or other place of business in the District
• Has any representative, agent, salesman, canvasser, or solicitor operating in the District in order to make sales at retail or take orders for such sales
  

See the Office of Tax and Revenue, Tax Guide Nexus; Code of the District of Columbia, Section 47-2201. Definitions.