Texas Family Code - FAM § 8.0591. Overpayment

(a) If an obligor is not in arrears on the obligor's maintenance obligation and the obligor's maintenance obligation has terminated, the obligee must return to the obligor any maintenance payment made by the obligor that exceeds the amount of maintenance ordered or approved by the court, regardless of whether the payment was made before, on, or after the date the maintenance obligation terminated.

(b) An obligor may file a suit to recover overpaid maintenance under Subsection (a).  If the court finds that the obligee failed to return overpaid maintenance under Subsection (a), the court shall order the obligee to pay the obligor's attorney's fees and all court costs in addition to the amount of the overpaid maintenance.  For good cause shown, the court may waive the requirement that the obligee pay attorney's fees and court costs if the court states in its order the reasons supporting that finding.