IMPORTATION FOR STORAGE, USE, OR CONSUMPTION PRESUMED.
Tex. TAX Code § 151.105.
in effect(a) Tangible personal property that is shipped or brought into this state by a purchaser is presumed, in the absence of evidence to the contrary, to have been purchased from a retailer for storage, use, or consumption in this state.
(b) A taxable service used in this state is presumed, in the absence of evidence to the contrary, to have been purchased from a retailer for use in this state.