would this be it?
§ 154.014. PAYMENTS IN EXCESS OF COURT-ORDERED
AMOUNT. (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.
Added by Acts 2001, 77th Leg., ch. 1491, § 2, eff. Jan. 1, 2002.
Renumbered from V.T.C.A., Family Code § 154.013 by Acts 2003,
78th Leg., ch. 1275, § 2(52), eff. Sept,2003