S.C. Code Ann. § 20-7-1024 – Continuing jurisdiction

(A) 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.
(B) A tribunal of this State may not modify a spousal-support order issued by a tribunal of another state having continuing, exclusive jurisdiction over that order under the law of that state.
(C) A tribunal of this State that has continuing, exclusive jurisdiction over a spousal-support order may serve as:
1. (1) an initiating tribunal to request a tribunal of another state to enforce the spousal-support order issued in this State; or
2. (2) a responding tribunal to enforce or modify its own spousal-support order.
  PART III. CIVIL PROVISIONS OF GENERAL APPLICATION