S.C. Code Ann. § 8-1-145: Irrevocable resignation of elected office holder to take effect in future; election to fill vacancy.

(A) A person holding an office in this State filled by a vote of qualified electors may submit a written irrevocable resignation from that office which is effective on a specific date.

(B) An election must be held in accordance with the provisions of Section 7-13-190 or other applicable provisions of law to fill the office to be vacated as if the vacancy occurred on the date the written irrevocable resignation is submitted.

(C) The newly elected official may not take office until the vacancy actually occurs.