S.C. Code Ann. § 12-28-925
Each supplier and bonded importer who sells taxable motor fuel shall collect from the purchaser the motor fuel tax imposed under Section 12-28-310. At the election of an eligible purchaser evidenced by a written statement from the department as to the purchaser eligibility status as determined under Section 12-28-930, the seller may not require a payment of motor fuel tax on transport truckloads from the purchaser sooner than one business day before the date on which the tax is required to be remitted by the supplier or bonded importer under Section 12-28-915. This election is subject to a condition that the eligible purchaser's remittances of all amounts of tax due the seller must be paid by electronic funds transfer. Failure of a supplier or bonded importer to comply with the requirements of this section may result in suspension or revocation of the license in accordance with Section 12-28-1180(B). The eligible purchaser's election under this subsection may be terminated by the seller if the eligible purchaser does not make timely payments to the seller as required by this section.