과오납금 환급 시 국세환급금에 적용할 이자율에 관한 연구

This study paper addresses the question of which ought to be applied to the additional refund of national taxes in case of refund of erroneously paid or overpaid national taxes, among the interest rate of additional refund of national taxes or the statutory interest rate prescribed in the Korean Civil Code. The summary of the discussion in this paper is as follows. First, the Supreme Court's precedent states that if a national tax refund (the right to refund an erroneous or overpaid payment) is delayed, claims due to the additional refund and the delayed damages arising from the statutory interest will compete with each other. Such logic seems to presuppose that the right to claim the return of an erroneous or overpaid payment is a private right realized through a civil action. However, it is thought that the reason of our practitioners constructing the lawsuit for refund an erroneous or overpaid payment on a private law basis and resolving it through civil lawsuits comes from not the theoretical context but the historical context. At the present time when the litigation system for the public legal system is in place, defining the legal nature of the claim for refund of an erroneous or overpaid payment based on the procedural reason is deemed to put the cart before the horse. Second, the current prevailing view is that the right to claim the refund of an erroneous or overpaid payment falls under public rights in that there is the state’s public power behind the legal relationship. If the foregoing rights are viewed as public rights, then the application of judicial provisions should be restrictive and possible only to the extent that the provisions of public law are flawed and, by their nature, do not prejudice the particularity of public law. However, if Article 397 of the Korean Civil Code is applied to a request for refund of an erroneous or overpaid payment, the financial burden of the state will fluctuate according to the taxpayer’s choice, impairing the principle of constitutional state and the public nature of tax liability. Therefore, it is considered unnecessary to apply or analogically apply the provisions of the Civil Code to the refund of an erroneous or overpaid payment. Thirdly, while the Supreme Court assumes that the legal nature of the additional refund for the refund of an erroneous or overpaid payment is the statutory interest on unfair gains, the prevailing opinion in Japan assumes it as damages. There being a lack of domestic debate, when we refer to the debate in Japan, both the additional refund and the delayed interest will have the nature of damages, and the basic assumption of the Supreme Court recognizing the competition of claims is considered to be difficult to survive. Fourth, if the Supreme Court's traditional position is maintained, it is possible to assert that the State would collect penalty tax on late payment applying the Article 397 of the Civil Code. Finally, there is a sharp difference between the interest rate under the Korean Civil Code and additional refund of an erroneous or overpaid payment, which explains why the issues discussed in this study are rare and difficult to find in other countries. As of April 1. 2020, the former exceeds twice the latter. Therefore, it is necessary to take legislative measures to reduce the difference.