Texas Tax Code - TAX § 162.117. Duties of Seller of Gasoline

(a) A seller who receives or collects tax holds the amount received or collected in trust for the benefit of this state and has a fiduciary duty to remit to the comptroller the amount of tax received or collected.

(b) A seller shall furnish the purchaser with an invoice, bill of lading, or other documentation as evidence of the number of gallons received by the purchaser.

(c) A seller who receives a payment of tax may not apply the payment of tax to a debt that the person making the payment owes for gasoline purchased from the seller.

(d) A person required to receive or collect a tax under this chapter is liable for and shall pay the tax in the manner provided by this chapter.