District of Columbia Code Division VIII. General Laws. § 47-3907. Credit.

(a) To prevent actual multi-state taxation of the sale of toll or wireless telecommunication service, the taxpayer, upon proof that it has paid a properly due excise, sales, use, or gross receipts tax in another jurisdiction on a sale that is subject to taxation under this chapter, shall be allowed a credit against the tax for the amount paid, but in no event shall the credit exceed the tax imposed under this chapter.

(b) A taxpayer may be allowed an alternate method for reporting the credit upon showing to the satisfaction of the Mayor that it does not have the capability through reasonable measures to determine the credit. The showing may be made by a petition to the Mayor which includes the factual basis for the inability to determine the credit through reasonable measures, and an alternate method of reporting the credit that the taxpayer believes is reasonable and equitable.