S.C. Code Ann. § 40-63-560

Active duty military personnel, or their spouse, shall designate a home state where the individual has a current license in good standing. The individual may retain the home state designation during the period the service member is on active duty. Subsequent to designating a home state, the individual may only change their home state through application for licensure in the new state, or through the process outlined in Section 40-63-550.