(1) Where a taxpayer has filed a return (including preliminary returns and interim returns, but excluding returns of persons who are not financial or insurance business entities from among returns prescribed in Article 9 of the Education Tax Act and excluding returns under the Act on Special Rural Development Tax) on the tax base of national tax pursuant to the tax-related statutes within the statutory due date of return, but he or she has reported the tax amount he or she should pay less than the amount he or she should report (hereinafter in this Article and Article 48, referred to as "underreporting") or has reported the tax amount to be refunded more than the amount he or she should report (hereinafter in this Article and Article 48, referred to as "overreporting"), amounts obtained by applying the following calculation methods to the aggregate amount of the underreported tax amount to be paid and the overreported tax amount to be refunded (where he or she should pay an additional tax under this Act and the tax-related statutes and an additional amount equivalent to the interest he or she should pay by adding thereto pursuant to the tax-related statutes, such amounts shall be excluded; hereinafter referred to as "underreported tax amount to be paid, etc.") shall be additional taxes: <Amended on Dec. 20, 2016; Dec. 19, 2017; Dec. 31, 2019>
1. In cases of underreporting or overreporting due to an unlawful act: The aggregate of the following amounts:(a) An amount equivalent to 40/100 (in cases of underreporting caused by an unlawful act in cross-border trades, 60/100) of the underreported tax amount to be paid, etc., caused by an unlawful act;(b) An amount equivalent to 10/100 of the amount obtained by subtracting the underreported tax amount to be paid, etc., caused by an unlawful act, from the underreported tax amount to be paid, etc.;
2. Cases other than subparagraph 1: An amount equivalent to 10/100 of the underreported tax amount to be paid, etc.
(2) Notwithstanding paragraph (1), in any of the following cases, an amount specified in the relevant subparagraph shall be an additional tax: <Amended on Jan. 1, 2013; Jun. 7, 2013; Dec. 23, 2014; Dec. 20, 2016>
1. Where a person who has underreported by an unlawful act for the reports prescribed in Articles 70 and 124 of the Income Tax Act or in Articles 60, 76-17 and 97 of the Corporate Tax Act is a person subject to double-entry bookkeeping or a corporation: An amount obtained by adding an amount prescribed in paragraph (1) 1 (b) to the greater of the two following amounts:(a) An amount prescribed in paragraph (1) 1 (a);(b) An amount calculated by multiplying the amount of revenue related to the tax base underreported by an unlawful act, by 14/10,000;
2. Where a business entity prescribed in the Value-Added Tax Act has filed a return under Articles 48 (1) and (4), 49 (1), 66 and 67 of the same Act, but has underreported the zero-rate tax base or has failed to file a return on such tax base: The aggregate amount of an amount specified in the relevant subparagraph of paragraph (1) and an amount equivalent to 5/1,000 of the zero-rate tax base underreported or non-reported.
(3) Paragraphs (1) and (2) shall also apply to the case where a person other than an enterprise under the Value-Added Tax files a return on refunded tax amount.
(4) When applying paragraph (1) or (2), an additional tax under paragraph (1) or (2) shall not apply to the underreported or overreported portion in relation thereto, in any of the following cases: <Amended on Jun. 7, 2013; Dec. 23, 2014; Dec. 15, 2015; Dec. 19, 2017; Dec. 31, 2022; Dec. 31, 2023>
1. Where the tax base of inheritance tax or gift tax is underreported due to any of the following causes:(a) Where inherited tax or gifted tax is not confirmed due to the reasons such a lawsuit for its ownership at the time of filing a return;(b) Where there is an error in the application of deduction under Articles 18, 18-2, 18-3, 19 through 23, 23-2, 24, 53, 53-2, and 54 of the Inheritance Tax and Gift Tax Act;(c) Where a tax base is determined with the value appraised under Articles 60 (2) and (3) and 66 of the Inheritance Tax and Gift Tax Act (excluding cases of fraudulent underreporting of the tax base for inheritance tax and gift tax);(d) Where a profit deemed donation under the provisions of Articles 45-3 through 45-5 of the Inheritance Act and Gift Tax Act varies due to the determination or correction of the corporate tax base and tax amount pursuant to Article 66 of the Corporate Tax Act (excluding cases that the corporate tax base and tax amount are determined or corrected due to an unlawful act);1-2. Where the tax base of capital gains tax on the portion deemed transferred at the time of granting a gift of encumbered property under the latter part, with the exception of the items, of subparagraph 1 of Article 88 of the Income Tax Act is determined or corrected (excluding cases where the tax base of capital gains tax is underreported by an unlawful act) based on the value assessed pursuant to Article 60 (2) and (3) and Article 66 of the Inheritance Tax and Gift Tax Act;
2. Where the proviso of Article 45 (3) of the Value-Added Tax Act applies;
3. Where acquisition values of stocks, etc. defined in subparagraph 2 of Article 88 of the Income Tax Act are reduced due to a ground falling under subparagraph 1 (d).
4. Where the person fails to meet the requirements for tax credit due to any unavoidable causes prescribed by Presidential Decree after he or she receives a tax credit pursuant to Article 24 of the Act on Restriction on Special Cases concerning Taxation.
(5) Deleted. <Dec. 23, 2014>
(6) Article 47-2 (5) and (6) shall apply mutatis mutandis to the imposition of additional taxes under this Article. <Amended on Dec. 23, 2014; Dec. 22, 2020>
(7) Matters necessary for the calculation of the underreported tax amount to be paid, etc. due to an unlawful act and the imposition of additional taxes, shall be prescribed by Presidential Decree. <Amended on Dec. 23, 2014>[This Article Wholly Amended on Dec. 31, 2011]