Tex. Tax Code § 158.058

If the sales tax imposed by this chapter has previously been paid to the manufacturer by a retailer whose first sale at retail is to a resident of another state and if the manufactured home is transported to and installed on a homesite outside of this state and not titled or registered in this state, the retailer is entitled to a credit or refund of the tax previously paid under this chapter. No credit or refund is due or may be paid if any use or occupancy of the manufactured home occurred prior to the first sale at retail by the retailer.