D.C. Code § 47-1804.04

If a person reports any portion of his income from installment sales for federal income tax purposes under § 453 of the Internal Revenue Code of 1986 (§ 453 of Title 26, United States Code ) and as the same may hereafter be amended and if such income is subject to tax under this chapter, he may report such income under this chapter in the same manner and upon the same basis as the same was reported by him for federal income tax purposes, if such method of reporting is accepted and approved by the Commissioner of Internal Revenue.