S.C. Code § 5-27-180
In any county containing a city having a population of more than eighty-five thousand and less than one hundred thousand, according to the latest official United States census, the city engineer of such city and the county engineer of such county may name any street or road beyond the borders of such incorporated city or town and may change and give a number to designate each lot of land facing and fronting on such street or road for a distance of every twenty-six feet. A copy of the plat, and any revisions thereof, showing the street or road to be named and lots to be numbered shall be filed with the county engineer before he or the city engineer may name any street or road or give a number to any lot thereon. The street or road shown on such plat shall be located and referenced with an existing named street or road or a fixed or natural marker. Any such name or any number designating such a lot facing on a street or road, when made, shall be certified to the office of the clerk of court of such county for recording.
S.C. Code § 5-27-180