S.C. Code § 9-3-540
Delinquent payments due under Section 9-3-520 must be charged interest compounded annually based on the adjusted prime rate charged by banks, rounded to the nearest full percent. The effective date of the adjustment must be based on the twelve-month period ending March thirty-first of any calendar year and must be established by April fifteenth for an effective date of the next first day of July. The adjusted prime rate charged by banks means the average predominant prime rate quoted by commercial banks to large businesses as determined by the Board of Governors of the Federal Reserve System. The adjusted prime rate used must be the adjusted prime rate charged by the bank during March of that year. Delinquent payments may be recovered by action in a court of competent jurisdiction against the political subdivision liable therefor or may, at the request of the state agent, be deducted from any other monies payable to such subdivision by any department or agency of the State. Upon notification of the state agent to the State Treasurer and Comptroller General as to a delinquency of any payments due under Section 9-3-520 or of the failure of any political subdivision to make required reports, any distributions which might otherwise be made to the political subdivision from any funds of the State shall be withheld from such political subdivision until notice from the state agent to the State Treasurer that such political subdivision is no longer in default in its payments or in filing the required reports.
S.C. Code § 9-3-540