D.C. Mun. Regs. tit. 9, r. 9-3501
A gross receipts tax shall be imposed on telecommunication companies beginning July 1, 1986.
For the period beginning July 1, 1986, and ending June 30, 1987, the twelve (12) monthly affidavits shall be combined on one affidavit which is due on October 30, 1987.
The tax for the period beginning July 1, 1986, and ending June 30, 1987, shall be paid in two (2) equal installments before November 1, 1987, and before January 1, 1988.
The Mayor may, upon written application made before the date prescribed for payment of the tax, grant a reasonable extension of time for paying the tax under §§ 3501.3 and 3502.2 of this chapter whenever good cause exists for the extension.
Each telecommunication company shall be allowed a credit against the gross receipts tax imposed for the amount of personal property tax paid on the tax year 1987 return due by July 31, 1986 (for the period beginning July 1, 1986 and ending July 30, 1987).
D.C. Mun. Regs. tit. 9, r. 9-3501