S.C. Code Ann. § 12-37-3150
(A) For purposes of determining when a parcel of real property must be appraised, an assessable transfer of interest in real property includes, but is not limited to, the following:
(11) the passage of twenty years since the later of the base year or the last assessable transfer of interest for real property owned by a publicly-held entity whose stock, shares, or other ownership interests are traded on a regulated exchange, a pension fund, or other similar entity.
An assessable transfer of interest resulting in the appraisal required pursuant to this article occurs at the time of execution of the instruments directly resulting in the transfer of interest and without regard as to whether or not the applicable instruments are recorded. Failure to record instruments resulting in a transfer of interest gives rise to no inference as to whether or not an assessable transfer of interest has occurred.
(B) An assessable transfer of interest does not include:
(1) transfers not subject to federal income tax in the following circumstances:
(f) 721 (Nonrecognition of Gain or Loss on a Contribution to a Partnership).
Number references in the above subitems are to sections of the Internal Revenue Code of 1986, as defined in Section 12-6-40;