S.C. Code Ann. § 37-3-205

With respect to a consumer loan, refinancing, or consolidation, the lender may by agreement with the debtor refinance the unpaid balance and may contract for and receive a loan finance charge based on the principal resulting from the refinancing at a rate not exceeding that permitted by the provisions on loan finance charge for consumer loans (Section 37-3-201) or the provisions on loan finance charge for supervised loans (Section 37-3-508), whichever is appropriate. For the purpose of determining the loan finance charge permitted, the principal resulting from the refinancing comprises the following: (1) if the transaction was not precomputed, the total of the unpaid balance and the accrued charges on the date of the refinancing, or, if the transaction was precomputed, the amount which the debtor would have been required to pay upon prepayment pursuant to the provisions on rebate upon prepayment (Section 37-3-210) on the date of refinancing, except that for the purpose of computing this amount no minimum charge (Section 37-3-210) shall be allowed; and (2) appropriate additional charges (Section 37-3-202), payment of which is deferred.