Employers in the District of Columbia must conform with these state rules relating to filing income tax withholding returns.
Periodic Returns. Monthly (Form FR-900M) by 20th day of month following month being reported. Quarterly (FR-900Q) on or before the 20th day of the quarter following the period being reported. Annually (Form FR-900A) by January 20 of the year following the end of the reporting period.
Annual Reconciliation Returns. Form FR-900B due by January 31.