(a) In each subsequent sale of diesel fuel on which the tax has been paid, the tax imposed by this subchapter shall be collected from the purchaser so that the tax is paid ultimately by the person who uses the diesel fuel. Diesel fuel is considered to be used when it is delivered into a fuel supply tank.
(b) The tax imposed by this subchapter must be stated separately from the sales price of diesel fuel and identified as diesel fuel tax on the invoice or receipt issued to a purchaser. Backup diesel fuel tax may be identified as diesel fuel tax. The tax must be separately stated and identified in the same manner on a shipping document, if the shipping document includes the sales price of the diesel fuel.

(c) Except as provided by Subsection (d), the sales price of diesel fuel stated on an invoice, receipt, or shipping document is presumed to be exclusive of the tax imposed by this subchapter. The seller or purchaser may overcome the presumption by using the seller’s records to show that the tax imposed by this subchapter was included in the sales price.
(d) Subsection (b) does not apply to a sale of diesel fuel by a licensed dealer to a person who delivers the diesel fuel at the dealer’s place of business into a fuel supply tank or into a container having a capacity of not more than 10 gallons.