S.C. Code Ann. § 29-3-310: Request for entry of satisfaction.

Any holder of record of a mortgage who has received full payment or satisfaction or to whom a legal tender has been made of his debts, damages, costs, and charges secured by mortgage of real estate shall, at the request by certified mail or other form of delivery with a proof of delivery of the mortgagor or of his legal representative or any other person being a creditor of the debtor or a purchaser under him or having an interest in any estate bound by the mortgage and on tender of the fees of office for entering satisfaction, within three months after the certified mail, or other form of delivery, with a proof of delivery, request is made, enter satisfaction in the proper office on the mortgage which shall forever thereafter discharge and satisfy the mortgage.