D.C. Mun. Regs. tit. 9, r. 9-801
Each licensed importer of motor vehicle fuel into the District of Columbia shall keep permanent books showing purchases, transfers, sales, or other dispositions and uses of motor vehicle fuel.
The records required under § 801.1 shall include bookkeeping records of daily opening and closing inventories of motor vehicle fuel subject to the provisions of the Act.
All bookkeeping records of purchases shall be supported by invoices or other shipping data, and all sales, transfers, or other dispositions, shall be supported by delivery tickets and a monthly record by customers, except in cases of retail sales.
All accounting records shall be maintained so that they can be readily reconciled with the monthly return filed with the Deputy Chief Financial Officer.
D.C. Mun. Regs. tit. 9, r. 9-801