Utah Code § 81-8-211: Continuing, exclusive jurisdiction to modify spousal support order.

(1) A tribunal of this state issuing a spousal support order consistent with the law of this state has continuing, exclusive jurisdiction to modify the spousal support order throughout the existence of the support obligation.

(2) A tribunal of this state may not modify a spousal support order issued by a tribunal of another state or foreign country having continuing, exclusive jurisdiction over that order under the law of that state or foreign country.

(3) A tribunal of this state that has continuing, exclusive jurisdiction over a spousal support order may serve as:

(a) an initiating tribunal to request a tribunal of another state to enforce the spousal support order issued in this state; or

(b) a responding tribunal to enforce or modify the tribunal's own spousal support order.