S.C. Code Ann. § 59-53-1880

For the purpose of developing and maintaining career and technology education facilities and programs to serve an area not exclusively within the boundaries of a single school district, the school districts serving this area are empowered to affiliate with each other under the terms and conditions, not in conflict with this section and Section 59-53-1890, as they see fit. The affiliation must be evidenced by a written instrument to be filed with the secretary and administrative officer of the State Board of Education and with the county boards of education concerned.