Texas Local Government Code - LOC GOV'T § 326.091. Sales and Use Tax

(a) If a district adopts the tax, there is imposed a tax on the receipts from the sale at retail of taxable items in the district at a rate of up to one-half of one percent. There is also imposed an excise tax on the use, storage, or other consumption in the district of taxable items purchased, leased, or rented from a retailer during the period that the tax is effective in the district.

(b) For purposes of this section, “taxable items” includes all items subject to any sales and use tax that is imposed by the county if the county has imposed a sales and use tax.