(a) If a child support agency or local child support registry receives from an obligor who is not in arrears a child support payment in an amount that exceeds the court-ordered amount, the agency or registry, to the extent possible, shall give effect to any expressed intent of the obligor for the application of the amount that exceeds the court-ordered amount.
(b) If the obligor does not express an intent for the application of the amount paid in excess of the court-ordered amount, the agency or registry shall:
(1) credit the excess amount to the obligor's future child support obligation; and
(2) promptly disburse the excess amount to the obligee.
(c) This section does not apply to an obligee who is a recipient of public assistance under Chapter 31, Human Resources Code.