The appeal is dismissed.

The costs of appeal are assessed against the Plaintiff.

The grounds of appeal are examined.

Tax in the method of tax return is, in principle, determined by the taxpayer's tax base and tax amount by the taxpayer's self-determination of the tax base and tax amount, and its payment is the performance of specific tax liability determined by the return, and the state holds the tax amount paid based on the final tax claim

Therefore, unless a taxpayer's filing of a return is null and void due to a significant and obvious defect, it cannot be deemed as an unjust enrichment.

In this context, the purpose, meaning, function, and legal remedies for defective reporting acts should be considered as a basis for the act of filing a report in a teleological context, and the specific circumstances leading to the act of filing a report should be individually identified and reasonably determined.

(See Supreme Court Decision 2006Da63464 Decided February 8, 2007, and Supreme Court Decision 2006Da81257 Decided April 23, 2009, etc.). In a case where an administrative disposition is rendered to a person who does not have any legal relation or factual relations subject to an administrative disposition, if there is an objective circumstance to mislead him/her that he/she is subject to an administrative disposition, the defect is significant and obvious. However, in a case where there is any objective circumstance to believe that any legal relation or factual relations, which is not subject to an administrative disposition, are subject to an administrative disposition, and it can only be discovered if it is confirmed that the factual relations are subject to an administrative disposition should be accurately examined, even if the mistake is serious, it is apparent that

(see, e.g., Supreme Court Decision 95Da46722, May 9, 1997). The lower court, based on its stated reasoning, cannot be deemed as null and void due to a significant and apparent defect in the act of reporting value-added tax on the instant business.