The judgment below is reversed and the case is remanded to Seoul High Court.

The grounds of appeal are examined.

1. Article 45-2(2) of the former Framework Act on National Taxes (amended by Act No. 13552, Dec. 15, 2015; hereinafter “the Act”) provides that “Any person who has filed a tax base return by the statutory due date of return, or who has received a decision on the tax base and amount of national taxes, may file a request for the decision or rectification within two months from the date on which he/she becomes aware of the occurrence of any of the following grounds,” and Subparag. 1 of the same Article provides that “if any transaction or act, etc., on which the tax base and amount of tax are calculated is based in the initial return, decision or correction (hereinafter “the first return, etc.”) is confirmed to be different by a final judgment (including reconciliation or other act having the same effect as the judgment) in the lawsuit pertaining thereto:

The purport of the ex post facto request for correction is to expand the protection of taxpayers’ rights by allowing taxpayers to file a request for reduction of their tax base and amount of tax when there occurs any change in the basis for calculating the tax base and amount of tax after the establishment of the tax liability. In this context, the term “when the transaction, act, etc. becomes final and conclusive as different by a ruling on the lawsuit related thereto” as provided in Article 45-2(2)1 of the Act refers to a case where a dispute over the transaction, act, etc. which served as the basis for calculating the tax base and amount of tax after the first declaration, becomes final and conclusive as the existence or legal effect of such transaction, act, etc. is different by a ruling in the relevant lawsuit, and thus the first declaration, etc. cannot be maintained properly.

(See Supreme Court Decision 2009Du22379 Decided July 28, 201, and Supreme Court Decision 2005Du7006 Decided January 26, 2006, etc.). In addition, the language and text and intent of the above provision are as follows.