Tex. Utilities Code § 55.132: NOTIFICATION OF CHANGE.

(a) The owner or operator of an automated dial announcing device shall notify the commission if the telephone number of the device or the physical address from which the device operates changes.

(b) The owner or operator shall give the notice by certified mail not later than the 48th hour before the hour the device begins operating with the new telephone number or at the new address.

(c) If the owner or operator of a device fails to give notice as required by Subsection (b), the person's permit is invalid.

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