S.C. Code Ann. § 20-1-100
Any person under the age of sixteen is not capable of entering into a valid marriage, and all marriages hereinafter entered into by such persons are void ab initio. A common-law marriage hereinafter entered into by a person under the age of sixteen is void ab initio.
Conflict of laws as to validity of marriage attacked because of nonage. 71 ALR2d 687.