Louisiana Revised Statutes Tit. 47, § 818.50. Fuel invoices required

A. For each delivery of gasoline or diesel fuel into the fuel supply tank of a highway vehicle subject to inspection as provided in R.S. 47:818.51, the required record shall include a serially numbered invoice issued in not less than duplicate counterparts on which shall be printed, or stamped with a rubber stamp the name and address of the entity making such delivery and on which shall be shown, in spaces to be provided on such invoice:

B. The invoice shall reflect that the tax has been paid or accounted for on each of the products delivered. One counterpart of the invoice shall be kept by the vendor, making such delivery as a part of his record and for the period of time and purposes established by the secretary. One counterpart shall be delivered to the operator of the highway vehicle and carried in the cab compartment of the highway vehicle for inspection by the secretary or his authorized designee, until the fuel it covers has been consumed.

C. For purposes of substantiating a tax refund claim, a computer-generated record from the seller of the fuel showing the required information may be substituted for the invoices required herein.