Of the part against the plaintiff in the lower judgment, the part concerning the decision on the tax investigation of corporate tax for the business year 2010.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. As to the decision of investigation of corporate tax for the business year 2010

A. Article 81-4(2) of the former Framework Act on National Taxes (amended by Act No. 11604, Jan. 1, 2013; hereinafter the same) provides that “Tax officials shall not re-examine the same items of taxation and the same taxable period, except in any of the following cases” to determine whether a case constitutes re-audit based on the items of taxation and the taxable period.”

In addition, Article 81-7(1) of the former Framework Act on National Taxes stipulates "tax items subject to investigation" as one of the matters to be notified before commencing a tax investigation, and Article 81-9(1) provides that "tax officials shall not extend the scope of tax investigation during the process of investigation, except in cases prescribed by Presidential Decree, such as where it is confirmed that specific suspicion of tax evasion exists for several taxable periods or is related to other items of tax."

Furthermore, Article 81-11 of the former Framework Act on National Taxes provides that "In principle, an tax investigation shall be conducted by combining tax items liable for return and payment in relation to the taxpayer's business, except as otherwise prescribed by Presidential Decree, such as where it is necessary to investigate specific tax items only

The text and structure of these relevant regulations, and the same tax items and the repeated tax investigation for the taxable periods may seriously infringe not only on taxpayers' freedom of business or legal stability, but also may lead to abuse of their right of tax investigation. Therefore, it is necessary to be prohibited from being prohibited except in exceptional cases that are clearly contrary to the principle of fair taxation and to prohibit re-audit.