D.C. Mun. Regs. tit. 9, r. 9-400
The District Sales Tax Act (D.C. Code §§ 47-2001 et seq.), as amended (which is referred to in this chapter as the "Act"), imposes a tax upon every vendor in the District selling certain tangible personal property at retail and selling certain selected services defined as selling at retail.
The tax is at the rates set forth in § 125 of the Act (D.C. Code § 47-2002) upon the entire gross receipts from taxable sales, as defined in the Act.
For the purposes of this chapter, the words, terms, and phrases defined in the Act shall have the same meanings when used in this chapter, unless otherwise required by the context of this chapter.
The provisions of this chapter (so far as applicable and with changes that are necessarily implied) are applicable to the Compensating Use Tax (See: D.C. Code §§ 47-2201 et seq.).
When used in this chapter, the term "Deputy Chief Financial Officer" shall mean the Deputy Chief Financial Officer of the Office of Tax and Revenue ("Office"), or his or her lawfully appointed agent, representative, or designee, and shall include the terms "Assessor" and "Collector" as used in the Act or prior rules and regulations.
When the due date for filing a return or paying a tax under the Act or this chapter falls on a Saturday, Sunday, or legal holiday, the last date for filing the return or paying the tax shall be the first business day following that Saturday, Sunday, or legal holiday.
Effective January 1, 1982, the District shall use a tax return system which is similar to the federal depository system for filing and payment of sales and use taxes.
D.C. Mun. Regs. tit. 9, r. 9-400