S.C. Code Ann. § 12-28-940 — Computing amount of motor fuel user fees due

(A) In computing the amount of motor fuel user fees due, the supplier is entitled to a credit against the user fee payable in the amount of the user fee paid by the supplier that is uncollectible from an eligible purchaser.
(B) The supplier shall provide notice to the department of a failure to collect user fees within ten days following the earliest date on which the supplier was entitled to collect the user from the eligible purchaser under Section 12-28-925.
(C) The department may promulgate regulations establishing the evidence a supplier shall provide to receive the credit.
(D) The credit must be claimed on the first return following the date of the failure of the eligible purchaser if the payment remains unpaid as of the filing date of that return or the credit is disallowed.
(E) The claim for credit must identify the defaulting eligible purchaser and any user fee liability that remains unpaid.
(F) If an eligible purchaser fails to make a timely payment of the amount of user fees due, the supplier's credit is limited to the amount due from the purchaser, plus any user fee that accrues from that purchaser for a period ending upon the date the supplier receives notice from the department of revocation of eligible purchaser status.
(G) No additional credit is allowed to a supplier under this section until the department authorizes the purchaser to make a new election under Section 12-28-925.