S.C. Code Ann. § 12-16-1140

The department may extend the time for the payment of the amount of tax required by this chapter for a reasonable period not to exceed twelve months. If the department finds that the payment on the due date of any part of the amount determined by the executor as the tax imposed by this chapter would result in undue hardship to the estate, it may extend the time for payment for a reasonable period not in excess of five years from the date prescribed by Section 12-16-1110.