Texas Utilities Code - UTIL § 40.057. Billing

(a) A municipally owned utility that opts for customer choice may continue to bill directly electric customers located in its certificated retail service area, as that area exists on the date of adoption of customer choice, for all transmission and distribution services.  The municipally owned utility may also bill directly for generation services and customer services provided by the municipally owned utility to those customers.

(b) A municipally owned utility that opts for customer choice may not adopt anticompetitive billing practices that would discourage customers in its service area from choosing a retail electric provider.

(c) A municipally owned utility that opts for customer choice and does not sell electric energy to retail customers is not required to bill directly for distribution, transmission, and generation services provided to retail electric customers located in its certificated service area.  A retail electric provider may provide billing services for distribution, transmission, and generation services provided to those customers.