Tex. Utilities Code § 104.004: UNREASONABLE PREFERENCE OR PREJUDICE PROHIBITED.

A gas utility may not:

(1) grant an unreasonable preference or advantage concerning rates or services to a person in a classification;

(2) subject a person in a classification to an unreasonable prejudice or disadvantage concerning rates or services; or

(3) establish or maintain an unreasonable difference concerning rates of services between localities or between classes of service.

Acts 1997, 75th Leg., ch. 166, Sec. 1, eff. Sept. 1, 1997.