S.C. Code Ann. § 63-17-2720

When the division determines that child support is unpaid in an amount equal to or greater than one thousand dollars, it shall send written notice to the obligor by first-class mail to the obligor's last known address, as filed with the tribunal pursuant to Section 63-17-450. The notice shall specify the amount unpaid as of the date of the notice or other date certain and the right of the obligor to request an administrative review by filing a written request with the division within thirty days of the date of the notice. If the obligor files a timely written request for an administrative review, the division shall conduct the review within thirty days of receiving the request.