The term "shortage/excess of duty collection” refers to cases in which shortfall or excess of duty collection resulted from conspicuous errors in tariff classifications, tariff rates, calculation of duty payable, particulars given in the duty memo, pricing unit, currency exchange rates, freights or insurance, etc., is discovered by Customs or by the duty-payer after the payment of import duty. The term "shortage/excess of duty refund" refers to cases in which shortage or excess of duty refund resulted from conspicuous errors in the calculation of refundable duty or any clerical mistakes in the refund notice is discovered by Customs or by the applicant of the refund.
    In the case of shortage/excess of duty collection or refund, Customs, upon discovery, shall notify the duty-payer and make up the difference. The duty-payer may also take initiative to apply for the payment or refund of the balance.
    Claiming or returning the difference shall be made within one year. For shortage/excess of duty collection, the time period shall commence from the date following the date the duty was paid. In case of shortage/excess of refund, the time period shall commence from the date following the date the duty refund notice was issued. The duty payable or refundable shall be collected or refunded along with daily interest  based on the fixed interest rate for one-year term time deposit of the postal savings on the date the duty is due or paid.
    The duty payer shall pay the insufficient balance or return the over-refunded amount along with the interest within 14 days following the date of receiving the notice from Customs. A delinquent fee shall be levied at the rate of 0.05 percent of the total amount of customs duty unpaid per day, commencing from the date following the date the prescribed payment period expired up to the date on which the outstanding amount of duty is liquidated in full. If the import duty remains unpaid for 30 consecutive days, the case will be forwarded to the competent court house for compulsory enforcement