Sections 207 and 209-210 are designed to span the gulf between the one-order system created by UIFSA and the multiple-order system previously in place under RURESA and URESA. UIFSA necessarily must provide transitional procedures for the eventual elimination of existing multiple support orders in an expeditious and efficient manner. But, even though all U.S. jurisdictions enacted UIFSA by 1998, many years will pass before its one-order system will be completely in place. Multiple orders covering the same parties and child number in the hundreds of thousands; it can be reasonably anticipated that some of these orders will continue in effect until nearly 2020. To begin the journey toward a one-order system, however, this section provides a relatively simple procedure designed to identify a single viable order that will be entitled to prospective enforcement in every UIFSA State.

Subsection (a) declares that if only one child support order exists, it is to be denominated the controlling order, irrespective of when and where it was issued and whether any of the individual parties or the child continue to reside in the issuing State.

Subsection (b) establishes the priority scheme for recognition and prospective enforcement of a single order among existing multiple orders regarding the same obligor, obligee, and child. The 2001 amendment to Subsection (b) clarifies that a tribunal requested to sort out the multiple orders and determine which one will be prospectively controlling of future payments must have personal jurisdiction over the litigants in order to ensure that its decision is binding on all concerned. For UIFSA to function, one order must be denominated as the controlling order, and its issuing tribunal must be recognized as having continuing, exclusive jurisdiction. In choosing among existing multiple orders, none of which can be distinguished as being in conflict with the principles of UIFSA, Subsection (b)(1) gives first priority to an order issued by the only tribunal that is entitled to continuing, exclusive jurisdiction under the terms of UIFSA, i.e., an individual party or the child continues to reside in that State and no other issuing State meets this criterion. If two or more tribunals would have continuing, exclusive jurisdiction under the Act, Subsection (b)(2) first looks to the