ADJUSTMENT FOR CHANGE IN TAX LIABILITY.

(a) The commission, on its own motion or on the petition of an electric utility, shall provide for the adjustment of the utility's billing to reflect an increase or decrease in the utility's tax liability to this state if the increase or decrease:

(1) results from Chapter 5, Acts of the 72nd Legislature, 1st Called Session, 1991; and

(2) is attributable to an activity subject to the commission's jurisdiction.

(b) The commission shall apportion pro rata to each type and class of service provided by the utility any billing adjustment under this section. The adjustment:

(1) shall be made effective at the same time as the increase or decrease of tax liability described by Subsection (a)(1) or as soon after that increase or decrease as is reasonably practical; and

(2) remains effective only until the commission alters the adjustment as provided by this section or enters an order for the utility under Subchapter C or D.

(c) Each year after an original adjustment, the commission shall:

(1) review the utility's increase or decrease of tax liability described by Subsection (a)(1); and

(2) alter the adjustment as necessary to reflect the increase or decrease.

(d) A proceeding under this section is not a rate case under Subchapter C.