(1) When the division of child support (DCS) decides that a determination of controlling order is required, or when a party, IV-D agency or jurisdiction asks for a determination of controlling order, DCS reviews the multiple child support orders for the same obligor and children to determine which order should be enforced.

(a) If DCS decides that the order that should be enforced is a Washington order, DCS refers the matter to the superior court for a determination of controlling order proceeding under chapter 26.21A RCW.

(b) If DCS decides that the order that should be enforced is an order which was not entered in the state of Washington, DCS follows the procedures set out in subsections (2) through (4) of this section.

(2) DCS serves a notice of support debt and registration as provided in WAC 388-14A-7100. DCS serves the notice of support debt and registration on the obligor, the obligee, and on all identified interested parties. The notice of support debt and registration includes a determination of controlling order.

(3) DCS serves the notice of support debt and registration on a party who did not request the determination of controlling order by certified mail, return receipt requested, or by personal service.

(4) DCS serves the notice on the party who requested the determination of controlling order and on any other identified interested parties by first class mail to the last known address.