S.C. Code Ann. § 12-8-600 — Withholding from any type of payment included in state gross income not specified in chapter; agreement by payee and payor; properly executed withholding exemption certificate deemed request for withholding

(A) A payee and payor may enter into an agreement to withhold income tax from any type of payment not otherwise provided in this chapter that is includable in South Carolina gross income. The agreement is effective for a mutually agreed upon period unless the payor or payee furnishes a signed written notice to the other party terminating the agreement.
(B) A properly executed withholding exemption certificate furnished by the payee to the payor constitutes a request for withholding. The amount to be withheld must be determined in accordance with this chapter and the tables and rules promulgated by the department with respect to withholding.