S.C. Const. art. VIII, § 5

Merger of parts of counties with adjoining counties. The General Assembly shall provide for the merger of a part or parts of a county with one or more adjoining counties upon request by the governing body of the county in which such part or parts are located, or upon petition by ten percent of the registered voters in the area desiring to transfer to another county. No merger shall take place unless two thirds of the qualified electors voting on the question in the territory to be transferred and a majority of the electors voting on the question in the county to which the territory is proposed to be annexed shall vote therefor. (1972 (57) 3184; 1973 (58) 67.)