S.C. Code Ann. § 63-17-3850: Enforcement of modification with in-state parties.

(A) If all of the parties who are individuals reside in this State and the child does not reside in the issuing state, a tribunal of this State has jurisdiction to enforce and to modify the issuing state's child-support order in a proceeding to register that order.

(B) A tribunal of this State exercising jurisdiction under this section shall apply the provisions of Parts I and II, this part, and the procedural and substantive law of this State to the proceeding for enforcement or modification. Parts III, IV, V, VII, and VIII do not apply.