The request for an extension of time to file must be made on or before the due date of the return and shall not extend the date for payment of the tax due.
Closing out separate entities. If an entity filed a District return on a separate reporting basis or on a District consolidated basis for the tax year beginning prior to January 1, 2011, and that entity will now be filing on a combined reporting basis for the tax year beginning after December 31, 2010, that entity (or entities), except for the designated agent, shall file a separate final zero return along with the combined report.
D.C. Mun. Regs. tit. 9, r. 9-176