Hi there-
I just went through the licensing requirements with DCRA, which requires people who rent their entire home (as opposed to a room in their home) to get a bed and breakfast license. In order to obtain a B&B license, you must register with the dc office of revenue, complete a basic business license form and obtain a certificate of occupancy from the zoning department. If you pull up the DCDRA website and enter the search for a B&B license, it will provide additional information. Unfortunately, you cannot complete all of the forms online so a trip to DCDRA is required. It took me the better part of a day to complete the requirements, which were confusing and required going to different divisions with DCDRA.
The clerk told me that most people do not comply. Oh, and come October, new regulations may take effect which prohibit how many nights you can rent your home out on air bnb or other home sharing sites. Hope this helps!