S.C. Code Ann. § 12-6-2280 — Sales factor; definitions

(A) The sales factor is a fraction in which the numerator is the total sales of the taxpayer in this State during the taxable year and the denominator is the total sales of the taxpayer everywhere during the taxable year.
(B) The term "sales in this State" includes sales of goods, merchandise, or property received by a purchaser in this State. The place where goods are received by the purchaser after all transportation is completed is considered the place at which the goods are received by the purchaser. Direct delivery into this State by the taxpayer to a person designated by a purchaser constitutes delivery to the purchaser in this State.
(C) Sales of tangible personal property to the United States government are not included in the numerator or the denominator of the sales factor. Only sales for which the United States government makes direct payment to the seller pursuant to the terms of a contract constitute sales to the United States government.
(D) For purposes of this section, items included in sales are as provided in Section 12-6-2295.