Tex. Util. Code § 37.151
Except as provided by Sections 37.152 and 37.153, a certificate holder shall:
Acts 1997, 75th Leg., ch. 166, Sec. 1, eff. Sept. 1, 1997.
Acts 2009, 81st Leg., R.S., Ch. 1170 (H.B. 3309), Sec. 4, eff. June 19, 2009.
Acts 2019, 86th Leg., R.S., Ch. 44 (S.B. 1938), Sec. 6, eff. May 16, 2019.