S.C. Code Ann. § 12-37-2725
When the title to a licensed vehicle is transferred, or the owner of the vehicle becomes a legal resident of another state and registers the vehicle in the new state of residence, the license plate and registration certificate may be returned for cancellation. The license plate and registration certificate must be delivered to the auditor of the county of the vehicle's registration and tax payment. A request for cancellation must be made in writing to the auditor upon forms approved by the Department of Motor Vehicles. The auditor, upon receipt of the license plate, registration certificate, and the request for cancellation, shall order and the treasurer shall issue a credit or refund of property taxes paid by the transferor on the vehicle. The amount of the refund or credit is that proportion of the tax paid that is equal to that proportion of the complete months remaining in that tax year. The auditor, within five days thereafter, shall deliver the license plate, registration certificate, and the written request for cancellation to the Department of Motor Vehicles. Upon receipt, the Department of Motor Vehicles shall cancel the license plate and registration certificate and may not reissue the same.