S.C. Code § 56-3-650
In order for inter-city bus companies operating fleets both in inter and intra state commerce in South Carolina to more efficiently dispatch individual buses in such fleets from one state to another, any such inter-city bus company operating a fleet of ten or more buses of thirty or more passenger capacity each may comply with the license requirements of this chapter by paying an in lieu license fee to the Department of Motor Vehicles. Such fee shall be an amount equivalent to an annual fee of two hundred dollars per bus, with the number of buses or fractions thereof determined by dividing the company's total bus travel mileage in this State in any one license year by forty thousand miles. Such an inter-city bus company shall declare at the beginning of each license year prior to May first respectively of each year the mileage its fleet operated in this State during the preceding calendar year, and shall pay to the department a total annual license fee for all such buses computed in accordance with this section. Any bus company licensed pursuant to this section must retain and hold, subject to audit by the department, for a period of at least four years all records used in computing the total mileage operated in the State during each calendar year. Bus companies electing to license under this provision shall not be required to display license plates as otherwise required by this chapter on the buses operated in South Carolina, but they shall have the option of displaying license plates on buses where such license plates are specifically identified with specific buses.
S.C. Code § 56-3-650