Texas Tax Code - TAX § 111.107. When Refund or Credit Is Permitted

(a) Except as otherwise expressly provided, a person may request a refund or a credit or the comptroller may make a refund or issue a credit for the overpayment of a tax imposed by this title at any time before the expiration of the period during which the comptroller may assess a deficiency for the tax and not thereafter unless the refund or credit is requested:

(b) A person may not refile a refund claim for the same transaction or item, tax type, period, and ground or reason that was previously denied by the comptroller.