S.C. Code § 12-36-2520
If the seller delivers tangible personal property to the purchaser in a state other than South Carolina and receives from the purchaser a statement, given under oath, that the property was purchased for storage, use, or consumption outside of South Carolina and that the property will not be returned for storage, use, or consumption in South Carolina, the sales or use tax due on the transactions will be transferred to the purchaser if the statement contains a description of the property, the date of sale, the amount of the purchase price, and the city and state of delivery. The statement must be retained by the seller and, upon request forwarded to the department. The department may forward a copy of the statement to the taxing authority of the state of delivery. If the property is subsequently stored, used, or consumed in this State, the purchaser, in addition to the sales or use tax, shall pay a penalty in an amount equal to fifty percent of the tax.
S.C. Code § 12-36-2520