B. The case affirming a claim for return of unjust enrichment on refund basis on the ground that the requirements for refund of the tax amount under Article 63 of the former Regulation of Tax Reduction and Exemption Act and Article 51 of the Enforcement Decree of the same Act have been satisfied with respect to the transfer of land where the transfer contract was concluded prior to the enforcement date

B. The case affirming a claim for return of unjust enrichment on refund basis on the ground that the requirements for refund of the tax amount under Article 63 of the former Regulation of Tax Reduction and Exemption Act and Article 51 of the Enforcement Decree of the same Act have been satisfied with respect to the transfer of land where the transfer contract was concluded prior to the enforcement date

The costs of appeal shall be borne by the defendant.

Article 63 of the Regulation of Tax Reduction and Exemption Act (amended by Act No. 3865 of Dec. 26, 1986) amended by Act No. 3865 of Dec. 26, 1986, and Article 1 of the Addenda of the same Act (amended by Presidential Decree No. 12564 of Dec. 31, 1988) provides that "The amended provisions of Article 10 (3) of the Addenda of the same Act shall apply to the first transfer/transfer/transfer/transfer after this Act enters into force," and the transfer prescribed by Article 4 (1) 3 and (3) of the Income Tax Act shall be construed as "transfer/transfer/transfer/transfer/transfer" regardless of the time of transfer/transfer/transfer/transfer/return" under Article 53 (1) of the Enforcement Decree of the same Act (amended by Presidential Decree No. 12564 of Dec. 31, 198).

The reason is that Article 2 of the Addenda to the amended Act provides that the tax liability and its content shall be determined by the law enforced at the time when the tax liability becomes effective upon completion of tax requirements under each tax law and that Article 2 of the Addenda to the amended Act shall be applied from the taxable year in which the enforcement date of this Act belongs, in the sense that the above transitional provision is applied to the case where the tax law is revised disadvantageous after the act causing taxation and the point at which the act subject to taxation is completed comes after the enforcement date of the amended tax law, if Article 2 of the Addenda to the above general law is applied to the case where the above general law becomes effective after the enforcement date of the amended tax law, it would be contrary to the trust of the taxpayer in relation to the existence of tax liability and its content. In order to protect the trust of the taxpayer, Article 10 (3) of the Addenda to the above amended Act shall be deemed to have been added for the purpose of protecting the trust of the taxpayer.

Therefore, as in the case of this case, Article 63 of the former Regulation of Tax Reduction and Exemption Act and Article 51 of the Enforcement Decree of the same Act shall apply to the transfer of the land of this case, which had been a transfer contract prior to the enforcement date of the amended Regulation of Tax Reduction and Exemption Act as seen in the above, and since the court below determined that the actual and procedural requirements for refund have been fully satisfied, the defendant has a duty to return the refund money as unjust enrichment. Therefore, the judgment of the court below has a duty to return it as unjust enrichment. Although it is not just because it is partially inconsistent with the above legal principles and it is the conclusion that the plaintiff accepted the plaintiff's claim

Therefore, the appeal is dismissed. It is so decided as per Disposition by the assent of all participating judges.

Justices Yoon Young-young (Presiding Justice)