Texas Utilities Code - UTIL § 41.057. Billing

(a) An electric cooperative that opts for customer choice may continue to bill directly electric customers located in its certificated service area for all transmission and distribution services. The electric cooperative may also bill directly for generation and customer services provided by the electric cooperative or its subsidiaries to those customers.

(b) A customer served by an electric cooperative for transmission and distribution services and by a retail electric provider for retail service has the option of being billed directly by each service provider or receiving a single bill for distribution, transmission, and generation services from the electric cooperative.