S.C. Code Ann. § 63-17-310: Family Court authority to enforce orders.

The family court has the authority to enforce the provisions of any decree, judgment, or order regarding child support of a court of this State, including cases with jurisdiction based on the revised Uniform Reciprocal Enforcement of Support Act, provided that personal jurisdiction has been properly established. This authority includes the right to modify any such decree, judgment, or order for child support as the court considers necessary upon a showing of changed circumstances. No such modification is effective as to any installment accruing prior to filing and service of the action for modification. Additionally, the family court has the right to hold any arrearage in child support in abeyance.