The Taxpayer Rights Protection Act Article 21

If a taxpayer is dissatisfied with a tax assessment and, after the recheck decision, files an appeal or administrative litigation, he or she may amend or add reasons why the tax assessment is illegal prior to the time when a decision is made by the administrative appeal review committee, or the end of oral argument in an administrative court adjudicating issues of facts, and the agency with jurisdiction of administrative appeal or the administrative court shall consider such reasons. The same applies when the agency with jurisdiction of administrative appeal or the administrative court finds ex officio that the tax assessment is illegal.In a case referred to in the preceding paragraph, the tax authorities shall file a reply and state specifically and clearly its opinions of the amended or added reasons.Administrative courts shall investigate evidence to verify taxpayers’ tax payable and determine the amount within the range set by a taxpayer’s challenge, except for complex cases which are difficult to investigate.During an administrative litigation filed by a taxpayer due to his or her dissatisfaction with the tax assessment, recheck, or administrative appeal, if the tax assessment, recheck, or administrative appeal is revoked or amended by a court because of illegality after the taking effect of this Act, and the tax payable has not become final after the expiry of a 15-year period from the day on which the judgment is made, the tax payable may no longer be assessed. However, if the tax payable has not become final due to the taxpayer’s intentional delay of the litigation process or caused by other reasons beyond the control of mankind, the tax payable may still be assessed.The preceding paragraph applies mutatis mutandis to the surcharge and belated surcharge (Article 20 of the Tax Collection Act ), interests, delinquent reporting surcharges, non-reporting surcharges, and fines.