D.C. Mun. Regs. tit. 9, § 4102
4102.1 The taxpayer subject to this section may be allowed an alternate method of reporting its monthly gross charges subject to the tax under this section upon showing to the satisfaction of the Mayor, before April 1, 1989, or thirty (30) days from the first day it becomes subject to this tax, whichever is later, or thirty (30) days from the first day a telecommunication company begins offering a new toll telecommunication service in the District, that it does not have the capability to identify the gross charges from the sale of toll telecommunication service that originates or terminates in the District and for which a charge is made to a service address located in the District regardless of where that amount is billed or paid.
4102.2 The showing shall be made by a petition to the Mayor which shall include the following information:
4102.3 The Mayor is authorized to employ a reasonable and equitable alternate method for reporting the gross charges of the taxpayer based on information submitted pursuant to this section or based on any other information made available to the Mayor.
SOURCE: Final Rulemaking published at 36 DCR 2478, 2484 (April 7, 1989).