Registration Questions What should I do to register as an employer with the District's Unemployment Compensation Program? How does an employer get an account number assigned in the District of Columbia? What should I do to register as an employer with the District's Unemployment Compensation Program? You need to complete Form FR-500, Combined Business Tax Registration Application.  This form can be filed over the Internet at cfo.dc.gov.  Click on Taxpayer Service Center, then on Business  Tax Service Center.  Scroll down and click on Combined Business Tax Registration Application FR-500.  The FR-500 Form is also available at the following locations: Department of Tax and Revenue Business Tax Registration Office 941 North Capitol Street, NE Washington, DC 20002 (202) 727-4829 Department of Employment Services Office of Unemployment Compensation Tax Division 609 H Street, NE, 3rd floor Washington, DC 20002 (202) 698-7550 Form FR-500 is used to provide the agency with information on ownership, location, and type of business, which is needed to make a determination of an employing unit's liability to pay unemployment taxes in the District of Columbia. Form FR-500 is also required when one employer acquires all or part of the assets of another employer. If completed off-line, the FR-500 should be completed in duplicate, with the employer retaining one copy. If completed on-line, the form should be printed before submittal to the Department of Tax and Revenue. Once a determination is made, employers will be advised by DOES whether they are liable or not, and if liable, when the liability began and the quarters for which tax reports and payments are due. How does an employer get an account number assigned in the District of Columbia? Employers are assigned a unique six-digit account number for unemployment insurance tax purposes early in the registration process. The account number assigned by DOES is different than an employer's Federal Employer Identification Number (FEIN) or the business tax number assigned by the District of Columbia Tax and Revenue Department. The DOES employer tax account number should be included in all correspondence concerning DC unemployment insurance taxes. Information for Employers Liability Tax Rates Reporting Employer Accounts