(a) A public utility shall file with the commission a tariff showing each rate that is:
(1) subject to the commission's jurisdiction; and
(2) in effect for a utility service, product, or commodity offered by the utility.
(a-1) An affiliate or trade association may file the tariff required under Subsection (a) on behalf of the public utility.
(b) The public utility, affiliate, or trade association shall file as a part of the tariff required under Subsection (a) each rule that relates to or affects:
(1) a rate of the utility; or
(2) a utility service, product, or commodity furnished by the utility.
(c) The tariff filing is considered approved if the commission does not approve or deny the tariff filing or request supplemental information from the public utility, affiliate, or trade association that filed the tariff before the 60th day after receiving the tariff filing.
(d) If the commission requests supplemental information from the public utility, affiliate, or trade association under Subsection (c), the utility, affiliate, or association must provide the commission with the supplemental information not later than the 15th day after receiving the request from the commission. If the commission does not approve or deny the tariff filing before the 30th day after the commission receives the supplemental information, the tariff filing is considered approved.