In order to add additional locations for billing, navigate to the Advanced Setup menu from the main menu and select Service Location.

Click on the  button from the top left. This will show the screen to add the new service location. Type in the Name, Code, Address, Zip, City, State, Country, Phone#, Fax, NPI#, POS, Legal Entity, Other External ID(s), Secondary ID Type, and the Secondary ID.

Click on Save when after entering the details and the new location for billing gets added.