Tex. Tax Code § 152.082
The taxes imposed by this chapter do not apply to the sale or use of a motor vehicle if the motor vehicle is operated with an exempt license plate issued under Section 502.451, Transportation Code, and is for use by:
(2) a commercial transportation company to provide transportation services under a contract with:
Acts 1981, 67th Leg., p. 1593, ch. 389, Sec. 1, eff. Jan. 1, 1982.
Amended by Acts 1997, 75th Leg., ch. 165, Sec. 30.257, eff. Sept. 1, 1997.
Acts 2013, 83rd Leg., R.S., Ch. 161 (S.B. 1093), Sec. 19.009, eff. September 1, 2013.
Acts 2015, 84th Leg., R.S., Ch. 844 (S.B. 724), Sec. 1, eff. June 17, 2015.