Tex. Local Government Code § 379A.083

(a) If the municipality adopts the tax, a tax is imposed on the receipts from the sale at retail of taxable items in the municipality at the rate approved at the election, and an excise tax is imposed on the use, storage, or other consumption in the municipality of tangible personal property purchased, leased, or rented from a retailer during the period that the tax is effective in the municipality. The rate of the excise tax is the same as the rate of the sales tax portion of the tax and is applied to the sale price of the tangible personal property.

(b) The adoption of the tax or the change of the tax rate takes effect on the first day of the first calendar quarter occurring after the expiration of the first complete quarter occurring after the date the comptroller receives a notice of the results of the election adopting, increasing, or decreasing the tax.