S.C. Code Ann. § 27-31-420
(A) Whenever a lessee, sole owner, or co-owner of a building declares the undertaking of a conversion of rental units to condominium ownership through the recordation of a master deed or master lease, within thirty days of the date of recordation the lessee or owner shall deliver in writing to each tenant in possession of an apartment within the building to be converted:
(3) an offer to convey to the tenant the apartment occupied by the tenant at a specified price and upon specified terms.
The tenant shall not be required to vacate the apartment until expiration of his lease or for one hundred twenty days, or ninety days if the tenant is under the age of sixty, following delivery of the notice, whichever is longer, and the terms of the tenancy shall not be altered during that period. Any notice which under the terms of such tenancy is required to be given to prevent the automatic renewal or extension of the term of such tenancy may be given during such period. Failure to give notice as required by this section shall constitute a defense to an action by the lessee or owner for possession if initiated less than one hundred twenty days, or ninety days if the tenant is under the age of sixty, after delivery of the notice, except as provided in subsection (E).
(D) Notices and offers required or permitted to be delivered to a tenant by this article may be:
(3) posted in the United States mails, postage prepaid, addressed to the tenant at the individual's apartment address.
Acceptances of offers of a lessee or owner may be: