Tex. Transportation Code § 453.404

Sec. 453.404. SALES TAX: EFFECTIVE DATES. (a) A transit department's sales and use tax takes effect on the first day of the second calendar quarter that begins after the date the comptroller receives a copy of the order required to be sent under Section 453.154.

(b) An increase or decrease in the rate of a transit department's sales and use tax takes effect on:

(1) the first day of the first calendar quarter that begins after the date the comptroller receives the notice provided under Section 453.403(c); or

(2) the first day of the second calendar quarter that begins after the date the comptroller receives the notice if within 10 days after the date of receipt of the notice the comptroller gives written notice to the presiding officer of the board that the comptroller requires more time to implement tax collection and reporting procedures.

(c) The presiding officer of the board of a transit department that imposes a sales and use tax under this chapter shall send to the comptroller by United States registered or certified mail a certified copy of each order of the municipality that created the transit department that adds territory to, or removes territory from, the municipality unless notice of the boundary change is given under Chapter 321, Tax Code. The order must give the effective date of the change and be accompanied by a map of the municipality clearly showing the territory added or removed. The tax is effective in the added territory or is excluded from the removed territory in the same manner as provided for a change of tax rate in Subsection (b).

(d) If the notice of a boundary change is given as provided by Chapter 321, Tax Code, the tax imposed under this chapter takes effect at the same time that the municipal tax takes effect under that notice.