If an auditor says, “Heavy additional tax will apply,” what are the requirements and what can be disputed?heavy additional taxis prescribed in Article 68 of the General Act of National Taxes.

This article helps taxpayers facing possible heavy additional tax and their tax accountants identify the facts open to challenge.

It replaces ordinary additional tax rather than being added on top

Heavy additional tax is imposedInsteadin place of additional tax for underreporting, nonfiling or nonpayment. Article 68(1), (2) and (3) each expressly says “in place of” the corresponding additional tax. Both are not imposed together.

These four collectively constitute additional taxes (Article 69); together with delinquent tax and interest tax, they are incidental taxes (Article 2).

Rates: 35%, 40% and 35%

Article 68(1), replacing underreporting additional tax, sets35%. Paragraph (2), replacing nonfiling additional tax, sets40%. Paragraph (3), replacing nonpayment additional tax, sets35%It is.

Each is multiplied by the tax amount underlying the ordinary additional tax calculation. However, where some underlying facts are clearly not concealed or fabricated, the tax attributable to those facts is calculated under Cabinet Order and deducted. Not every identified error is subject to heavy additional tax.

The requirement is “concealment or fabrication”

The statutory requirement is that the taxpayer, regarding all or part of the facts underlying the tax base or tax amount,conceals or fabricates those factsand files a return, or fails to file or pay, based on that concealment or fabrication.

The two-stage structure matters in practice: there must be concealment or fabrication, and the underreporting or similar result must ariseon that basis.Without that link, the requirement is unmet. Mere calculation errors or differences of interpretation are neither concealment nor fabrication.

Correction requests are also covered

Article 68(1) and (2) refer to “tax returns or correction requests under Article 23(3).” Concealment or fabrication in correction requests, not just returns, can therefore trigger heavy additional tax.

Amended returns filed without anticipating reassessment are excluded

Article 68(1) excludes cases where an amended return was not filed in anticipation of reassessment following an audit. Paragraph (2) similarly excludes filings without such anticipation and cases covered by Article 66(1)'s proviso or paragraph (9).

Paragraph (3) also excludes cases covered by Article 67(1)'s proviso, paragraph (2) or paragraph (3). The structure places voluntary corrections outside heavy additional tax.

A 10-percentage-point increase for repetition

Article 68(4) adds 10 percentage points where any of the preceding three paragraphs applies and either of the following conditions is met.

Item (i) covers prior nonfiling additional tax or similar charges for the same tax type during the five-year period counted back from the day before the late return, reassessment, determination, payment notice or unnotified payment. Item (ii) covers, among other cases, prior specified nonfiling additional tax or similar charges for the same tax type with tax periods beginning in the preceding two calendar years relative to the year in which the current period began.

Where paragraph (1) or (3) applies, only item (i) applies.

The seven-year assessment limit has separate requirements

In heavy-additional-tax cases, the time limit for reassessment or determination often extends to seven years. However, Article 70(5)(i) concerns taxes wholly or partly evaded or refunded through“deceit or other fraudulent acts,”wording distinct from Article 68's “concealment or fabrication.”

Although they often overlap in practice, the requirements are not identical. Do not assume a seven-year lookback automatically; apply each provision separately.

When liability arises and the minimum amount charged

Liability for heavy additional tax under Article 68(1), (2), and the related parts of (4) arisesExpiration of the statutory return deadline; liability under paragraph (3) and its related part of (4) arisesWhen the statutory payment deadline has passed(Article 15).

The tax base is rounded down to the nearest ¥10,000, the determined amount to the nearest ¥100, and the entire amount is discarded if below ¥5,000 (Articles 118 and 119).

Common practical questions

Most disputes concern factual findings: whose conduct constitutes concealment or fabrication, whether an employee's acts count as the taxpayer's, and when entries were created. Consult us before conceding during an audit so we can identify which facts affect the statutory requirements.

For the broader framework, see our overview of ancillary taxes.

Legal basis

• Article 2, Item 4 of the Act on General Rules for National Taxes (Definitions)
• General Act of National Taxes, Article 15(2)(xiv) and (xv) (Arising of tax obligations and determination of tax payable)
• General Act of National Taxes, Article 23(3) (Requests for correction)
• General Act of National Taxes, Article 68(1)–(4) (Heavy additional tax)
• Article 69 of the Act on General Rules for National Taxes (Tax Items Subject to Additional Taxes)
• General Act of National Taxes, Article 70(5)(i) (Time limits for reassessment, determination, etc.)
• Article 118, Paragraph 3 of the Act on General Rules for National Taxes (Rounding of Fractional Numbers for Tax Bases of National Taxes, etc.)
• Article 119, Paragraph 4 of the Act on General Rules for National Taxes (Rounding of Fractional Amounts of Established National Tax, etc.)

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