S.C. Code § 12-54-220
The department may permit the Commissioner of Internal Revenue of the United States, the proper officer of any state, or the authorized representative of either of these officers to inspect any return of any taxpayer or may furnish to the officer or his authorized representative an abstract of any return of any taxpayer, or supply him with information concerning any item contained in any return or disclosed by the report of any investigation of the return of any taxpayer. The permission is granted or the information furnished to the officer or his representative only if the statutes of the United States or of the other state, as the case may be, grant substantially similar privileges to the appropriate officer of this State. Information received as a result of an exchange of information between South Carolina and the Internal Revenue Service or any other state is not subject to the provisions of Chapter 4, Title 30, the Freedom of Information Act.
S.C. Code § 12-54-220