S.C. Code Ann. § 36-4-210
(a) A collecting bank has a security interest in an item and any accompanying documents or the proceeds of either:
(c) Receipt by a collecting bank of a final settlement for an item is a realization on its security interest in the item, accompanying documents, and proceeds. So long as the bank does not receive final settlement for the item or give up possession of the item or accompanying documents for purposes other than collection, the security interest continues to that extent and is subject to Chapter 9, but: