S.C. Code Ann. § 12-36-510
(A) Before engaging in business:
(B) A retail license is not required of:
(C) Retailers making sales at a special event, in lieu of the licensing requirements of this section and discount provisions of Section 12-36-2610, shall file a special events sales tax return.
For purposes of this subsection, the special event sales tax return may be used only for one special event and must be filed with the department together with the tax due within five days of the completion of the special event. However, the department may require payment upon demand.
"Special event" means a promotional show, trade show, fair, festival, or carnival for which an admissions fee is required for entering the event. In addition, the event must be operated for a period of less than twelve consecutive days.
The provisions of this subsection do not apply to retailers licensed under item (2) or (3) of subsection (A) of this section.