S.C. Code Ann. § 12-45-90

Taxes are payable in the following kinds of funds and no other: silver coin, United States currency, United States postal money orders, and checks subject to collection. A third-party administrator may be used for the collection of taxes through electronic media if there is no cost borne by the county. Other media of payment may be accepted as payment for taxes upon approval of the governing body, and if costs are incurred by the county in the acceptance of a payment media, approval of the county governing body must be obtained. Electronic or other media of payment are subject to collection, and in the absence of an agreement among the taxing entities to share the costs of collection of property taxes, costs must be apportioned among the taxing entities on a pro rata basis. The county governing body may impose a uniform surcharge as a condition of acceptance of a particular medium of payment, not to exceed the cost of accepting charge cards, debit cards, or electronic forms of payment including discount or merchant fees.