In the event that a taxpayer has made overpayment of any tax as a result of mis-application of tax law, mis-calculation by him or herself, or other mistakes that can be attributed to the taxpayer, an application for refund of such overpaid tax supported by substantial documentation may be filed within ten years from the date of payment thereof. Application for refund of such overpaid tax shall be denied if it is filed after the said ten-year period. But for a taxpayer has made overpayment of any tax as a result of a mistake that can be attributed to government agencies, an application for refund of such overpaid tax supported by substantial documentation may be filed within fifteen years from the date of payment thereof. Application for refund of such overpaid tax shall be denied if it is filed after the said fifteen-year period.
If the tax authority discovers the cause of a mistake within the time limit specified in the preceding paragraph, the overpaid tax shall be refunded within two years.
If the taxpayer is not satisfied with a tax assessment, has applied for administrative remedy, and the court makes a judgment, the provisions of the preceding paragraph shall not apply.
In the event that the overpayment of tax in the preceding Paragraph 1 was made by the taxpayer in cash, the tax authorities shall, based on the fixed interest rate on January 1 of each year for one-year time deposit of postal savings, calculate daily interest for such amount of overpaid tax starting from the date the overpaid amount was made till the documentation required by the internal procedures of the tax authorities for the refund of overpayment of tax is completed and such interest shall be added to the amount of the refund.
As for the enforcement of the amendment to this Article on November 30, 2021, where overpayment is made due to the reasons specified in the original Paragraph 1 and where the overpayment does not exceed the statutory 5-year time period for refund, the new Paragraph 1 shall apply; and where overpayment is made due to the reason stated in the original Paragraph 2, an application for refund shall be filed within fifteen (15) years from the enforcement of the amendment.
As for the enforcement of the amendment to this Article on November 30, 2021, for overpayment made due to the reasons specified in the original Paragraph 1 or the original Paragraph 2, should an application for refund be filed after the enforcement of the amendment, or should the application for refund be filed prior to the enforcement of the amendment and yet the overpaid tax is not refunded yet, or should the overpaid tax be refunded prior to the enforcement of the amendment and yet the refund is not yet confirmed, the provision of Paragraph 4 shall apply and interest calculated thereto should be added to the refund. However, should the provisions prior to the amendment be more favorable to the taxpayer(s), such provisions prior to the amendment shall apply.
Persons who know clearly that they have no obligations to pay taxes and yet still make tax payments in violation of tax laws or other laws and regulations shall not request a refund of such payments.

For the tax payment refundable to a taxpayer, the tax authorities shall offset the refundable taxes payable against the delinquent taxes receivable from a said taxpayer, and shall forthwith inform, by notice, said taxpayer of such offset.