S.C. Code § 56-23-85
A person connected with driver training schools or private, parochial, or public high schools shall not engage in either classroom only instruction, or behind the wheel only instruction, or both, unless the person has obtained and holds a valid driver instructor permit or temporary driver instructor permit issued by the Department of Motor Vehicles.
Appropriate examination for an instructor permit must be at the discretion of the department. The annual fee for an instructor permit is twenty dollars, and all instructor permits expire on June thirtieth. Public and private high school instructors are not required to pay a fee for a permit. The proceeds from the sale of instructor permits must be deposited in the state general fund.
S.C. Code § 56-23-85