10 CFR § 490.704 - Procedures and documentation.
(a) To receive a credit under this subpart, the fleet or covered person shall submit its request, on a form obtained from DOE, to the Office of Energy Efficiency and Renewable Energy, U. S. Department of Energy, EE-34, 1000 Independence Ave. SW., Washington, DC 20585, or such other address as DOE may publish in the Federal Register, along with the documentation required by paragraph (b) of this section.
(b) Each request for a credit under this subpart must be submitted on or before the December 31 after the close of the applicable model year and must include written documentation stating the quantity of biodiesel purchased, for the given model year, for use in vehicles weighing in excess of 8,500 lbs. gross vehicle weight;
(c) A fleet or covered person submitting a request for a credit under this subpart must maintain and retain purchase records verifying information in the request for a period of three years from December 31 immediately after the close of the model year for which the request is submitted.