S.C. Code Ann. § 7-15-430
Prior to the distribution of voter registration lists to the various precincts, the county board of registration shall note opposite the name of each registered voter who has voted by absentee ballot the fact of such voting or that an absentee ballot has been issued to a voter, as the case may be.
No voter whose name is so marked on the registration list as having voted shall be permitted to vote in person in his resident precinct and no voter who has been issued an absentee ballot may vote whether such ballot has been cast or not, unless he shall furnish to the officials of his resident precinct a certificate from the county board of registration that his absentee ballot has been returned to the board unmarked.
Should any voter be issued an absentee ballot after the registration board has released the registration books to be used in the election to the county election commission, municipal election commission, county committee, executive committee of any municipal party, or poll managers, the board of registration shall immediately notify in writing the county election commission, municipal election commission, county committee, executive committee of any municipal party, or poll manager, as the case may be, of the name, address, and certificate number of each voter who has since been issued an absentee ballot and the registration books must be appropriately marked that the voter has been issued an absentee ballot.