O.C.G.A. § 19-11-166 (2019)

(a) A party contesting the validity or enforcement of a registered support order or seeking to vacate the registration has the burden of proving one or more of the following defenses:

(1) The issuing tribunal lacked personal jurisdiction over the contesting party;

(2) The order was obtained by fraud;

(3) The order has been vacated, suspended, or modified by a later order;

(4) The issuing tribunal has stayed the order pending appeal;

(5) There is a defense under the law of Georgia to the remedy sought;

(6) Full or partial payment has been made;

(7) The statute of limitation under Code Section 19-11-163 precludes enforcement of some or all of the alleged arrearages; or

(8) The alleged controlling order is not the controlling order.

(b) If a party presents evidence establishing a full or partial defense under subsection (a) of this Code section, a tribunal may stay enforcement of a registered support order, continue the proceeding to permit production of additional relevant evidence, and issue temporary or other appropriate orders. Any portion of the registered support order which is not in dispute may be enforced by all remedies available under the laws of Georgia.

(c) If the contesting party does not establish a defense under subsection (a) of this Code section to the validity or enforcement of a registered support order, the registering tribunal shall issue an order confirming the order.