S.C. Code Ann. § 34-30-1640

A state savings bank or federal savings institution may continue to recognize the authority of an attorney-in-fact authorized in writing to manage or to make withdrawals either in whole or in part from a deposit account for an account holder, whether minor or adult, until it receives written notice or is on actual notice of the revocation of his authority. For the purposes of this section, written notice of the death or adjudication of incompetency of the account holder constitutes written notice of revocation of the authority of his attorney. A state savings bank is not liable for damages, penalty, or tax by reason of payment made pursuant to this section.