7 Tex. Admin. Code § 75.104
A motion for rehearing pursuant to Finance Code § 91.006 must be filed not later than the 14th day after the date the decision or order that is the subject of the motion is signed. A copy of the motion for rehearing must be served on all parties who made an appearance or otherwise submitted a filing in the proceeding, and the motion must include a certificate of service reciting the parties served and the method of service. A party must file a reply to the motion for rehearing, if any, not later than the 30th day after the date the decision or order that is the subject of the motion is signed. The Commissioner must act on the motion for rehearing not later than the 45th day after the date the decision or order that is the subject of the motion for rehearing is signed or the motion for rehearing is deemed overruled by operation of law.
7 Tex. Admin. Code § 75.104