S.C. Code Ann. § 12-8-580
(A)
(1) A person who purchases real property, or real property and associated tangible personal property, from a nonresident seller shall withhold:
(B)
(2)
(C)
(1) For purposes of this section, a nonresident is:
(2) However, a nonresident seller is considered a resident for purposes of this section if:
(a)
(D)
(E) The buyer may rely on an affidavit provided by the seller if the buyer does not know the affidavit is false and the seller, under penalties of perjury, states the following:
(F) If a withholding payment:
(2) contains a computational error;
the seller may file an amended nonresident withholding statement with the department and request a refund for any amount over withheld or pay any amount due.