In order to institute an action for divorce from the bonds of matrimony the plaintiff must have resided in this State at least one year prior to the commencement of the action or, if the plaintiff is a nonresident, the defendant must have so resided in this State for this period; provided, that when both parties are residents of the State when the action is commenced, the plaintiff must have resided in this State only three months prior to commencement of the action. The terms 'residents' or 'resided' as used in this section as it applies to a plaintiff or defendant stationed in this State on active duty military service means a continuous presence in this State for the period required regardless of intent to permanently remain in South Carolina.
This answer is for general advice. It is not legal advice and does not create an attorney client relationship. For legal advice you have to retain your own attorney.
I am not licensed in South Carolina, so you may want to double check with a local attorney. But according to my quick research, when both spouses are residents of the state when the action is filed, the plaintiff must have lived in SC for only three months before filing the action.
This information is intended as general information only. This communication does not establish an attorney-client relationship between me and the asker.