S.C. Code Ann. § 26-3-30 – Proof of authority

(a) If the notarial act is performed by any of the persons described in items (1) to (4), inclusive, of Section 26-3-20, other than a person authorized to perform notarial acts by the laws or regulations of a foreign country, the signature, rank or title and serial number, if any, of the person are sufficient proof of the authority of a holder of that rank or title to perform the act. Further proof of his authority is not required.
(b) If the notarial act is performed by a person authorized by the laws or regulations of a foreign country to perform the act, there is sufficient proof of the authority of that person to act if:
1. (1) Either a foreign service officer of the United States resident in the country in which the act is performed or a diplomatic or consular officer of the foreign country resident in the United States certifies that a person holding that office is authorized to perform the act;
2. (2) The official seal of the person performing the notarial act is affixed to the document; or
3. (3) The title and indication of authority to perform notarial acts of the person appear either in a digest of foreign law or in a list customarily used as a source of such information.
(c) If the notarial act is performed by a person other than one described in subsections (a) and (b), there is sufficient proof of the authority of that person to act if the clerk of a court of record in the place in which the notarial act is performed certifies to the official character of that person and to his authority to perform the notarial act.
(d) The signature and title of the person performing the act are prima facie evidence that he is a person with the designated title and that the signature is genuine.