S.C. Code Ann. § 12-28-970
(A) A backup user fee equal to the user fee imposed by Section 12-28-310 is imposed and must be administered in accordance with procedures established by the department on the use on the highways of motor fuel subject to the user fee by an end user, including operators of state and local government vehicles, American Red Cross vehicles, and buses, and other persons exempted from the full federal highway tax, unless the person is exempted otherwise under Section 12-28-710(A)(12), upon the delivery in this State into the fuel supply tank of a highway vehicle of:
(C)