D.C. Mun. Regs. tit. 9, r. 9-411
Each vendor who sells tangible personal property or provides services pursuant to a lump sum contract entered into prior to July 1, 1989, in which the taxable sales of property or services are included in the price of the contract with nontaxable sales or services, may allocate the taxable and nontaxable values in the contract according to the market value of the services or property provided.
This permission to allocate is not intended to limit the property or services subject to taxation; nor is it intended to authorize any expense deductions that may be part of the selling price of the property or services. This permission to allocate shall only apply to services that became subject to sales and use tax pursuant to the Revenue Amendment Act of 1989.
The Deputy Chief Financial Officer may request copies of contracts and other documentation to support an allocation made pursuant to § 411.1.
The Deputy Chief Financial Officer is authorized to disallow an allocation made under § 411.1, if it appears that the allocation does not fairly reflect the market value of the services or property provided.
If a vendor does not submit documentation in response to a request by the Deputy Chief Financial Officer, or if the Deputy Chief Financial Officer determines the allocation to be improper, the Deputy Chief Financial Officer may presume the full value of the contract is subject to the sales tax.
Service contracts entered into prior to July 1, 1989, and paid in full before July 1, 1989, shall not be subject to the tax.
Contracts for services performed and completed prior to July 1, 1989, but billed according to the terms of the contract on or after July 1, 1989, shall not be subject to the tax.
Service contracts entered into prior to July 1, 1989, where no services were performed before July 1, 1989, and where services were paid for when the contract was completed after July 1, 1989, shall be subject to the tax.
Service contracts entered into prior to July 1, 1989, where services were performed both before and after July 1, 1989, and where services were paid for when the contract was completed after July 1, 1989, shall be subject to the tax on the entire charge.
D.C. Mun. Regs. tit. 9, r. 9-411