Texas Tax Code - TAX § 151.102. User Liable for Tax

(a) The person storing, using, or consuming a taxable item in this state is liable for the tax imposed by Section 151.101 of this code, and except as provided by Subsection (b) of this section, the liability continues until the tax is paid to the state.

(b) A person storing, using, or consuming a taxable item in this state is not further liable for the tax imposed by Section 151.101 of this code if the person pays the tax to a retailer engaged in business in this state or other person authorized by the comptroller to collect the tax and receives from the retailer or other person a purchaser's receipt given as provided in Section 151.103 of this code.