Before the amendment to Article 38 of the Tax Collection Act, interest should be calculated at the interest rate of one-year term postal savings deposit on the actual tax payment date or the original due date. Under the amended Article 38, interest should be calculated at the interest rate on 1 January of each year of the administrative remedy procedure. In addition, interest should be paid/refunded along with the tax payable/refundable. This amendment applies to pending cases; provided, however, that if the calculation before Article 38 was amended is more favorable to the taxpayer, that calculation applies.