Overseas Financial Account Non-Reporting Penalty Calculator

What is the overseas financial account non-reporting penalty?

Korean residents and domestic corporations that hold financial accounts abroad must report them once the combined balance crosses a threshold.
If they fail to report, or under-report, an administrative fine (a “gwatae-ryo”) is charged under Article 90 of the Adjustment of International Taxes Act and Article 147 of its Enforcement Decree. This is a fine, not a tax surcharge (kasan-se) of the kind assessed in a tax audit.

Reporting is required when the aggregate balance of overseas financial accounts exceeds KRW 500 million on any month-end day during the year. Breaching the duty triggers a fine of 10% of the unreported amount, capped at KRW 1 billion.
This calculator estimates the non-reporting and under-reporting fine and the reduction available for a voluntary corrective filing, based on 2026 Korean rules.

Korea-based, 2026 rules. This tool reflects the Adjustment of International Taxes Act (Articles 53, 55, 56, 90), its Enforcement Decree (Articles 92, 147), the Punishment of Tax Offenses Act (Article 16), and the Framework Act on National Taxes (Article 85-5). It is a reference estimate and does not replace advice from a Korean tax professional. Actual fines can vary by ±50% at the tax authority’s discretion.

Who must report, when, and what?

1. Who is covered

Residents and domestic corporations that hold overseas financial accounts are covered.
Resident/domestic-corporation status is judged as of the year-end of the reporting year (Enforcement Decree Article 92).

• Nominee accounts: the nominal holder and the beneficial owner are each treated as holding the account.
• Joint accounts: each joint holder is treated as holding the entire balance.

2. The KRW 500 million threshold

The duty arises if the combined balance of overseas accounts exceeds KRW 500 million on any single month-end day during the year.
Because the peak month-end balance is what matters, reducing the balance by year-end does not remove the duty if any month-end exceeded the threshold.

💡 Balances across multiple accounts are aggregated, and each month-end balance is converted to KRW at that day’s standard exchange rate.

3. Reportable accounts and deadline

Deposits and savings, securities (stocks, bonds, funds), derivatives, and insurance are reportable, and so are overseas virtual-asset (cryptocurrency) accounts.
Accounts opened with overseas virtual-asset service providers became reportable from 2023 (Enforcement Decree Article 92, reflecting the 2025 amendment).

The filing period runs from 1 to 30 June of the following year, submitted to the head of the competent district tax office.
For example, accounts held during 2025 must be reported by 30 June 2026.

How the fine is calculated

The statute (Article 90(1)) sets only a ceiling of “up to 20% of the unreported or under-reported total” and delegates the detailed schedule to Enforcement Decree Article 147.
The current schedule applies a flat 10% rate with a KRW 1 billion cap.

Base fine formula

Base fine = min( unreported / under-reported amount × 10% , KRW 1 billion )

• Non-reporting: the base is the full account balance that should have been reported.
• Under-reporting: the base is the amount that should have been reported minus what was actually reported.
• Account-level amounts are summed, 10% is applied, and the result is capped at KRW 1 billion.
• In other words, once the unreported amount exceeds KRW 10 billion, the fine is fixed at KRW 1 billion.

Separate source-of-funds fine

If the tax authority asks the holder to explain the source of the violation amount (a 90-day window, extendable once by 60 days) and the holder fails to explain or explains falsely, a further 10% of the unexplained amount is charged.
This is waived where explanation is impossible due to force majeure or the circumstances of the account’s country.

A voluntary corrective or late filing generally removes the account from the source-explanation request (Article 56).

How much does voluntary filing reduce the fine?

Filing voluntarily before the authority imposes the fine — an amended filing to fix under-reporting, or a late filing to cure non-reporting — earns a mandatory reduction (Enforcement Decree Article 147(4)).
The reduction is denied if the holder files after already knowing the fine was coming.

Amended filing (fixing under-reporting)	Reduction
Within 6 months of the deadline	90%
6 months to 1 year	70%
1 to 2 years	50%
2 to 4 years	30%

Late filing (curing non-reporting)	Reduction
Within 1 month of the deadline	90%
1 to 6 months	70%
6 months to 1 year	50%
1 to 2 years	30%

Other adjustment factors

• ±50% discretion (Article 147(2)): the fine can be cut or raised by up to 50% based on severity, frequency, motive, and result — but never above the 20% statutory ceiling.
• Foreign-exchange report reduction (Article 147(3)): if the balance-status report under Foreign Exchange Transactions Act Article 20 was filed, the fine can be reduced by up to 50% (discretionary).
• Simple-error waiver (Article 147(6)): if a simple error such as a balance-aggregation mistake is recognized, the fine may not be imposed.

Above KRW 5 billion: criminal punishment and name disclosure

If the unreported or under-reported amount exceeds KRW 5 billion, criminal punishment and public name disclosure can run alongside the administrative fine.
This is the point where the matter escalates from an administrative fine to criminal exposure.

• Criminal punishment (Punishment of Tax Offenses Act Article 16): up to 2 years’ imprisonment or a fine of 13–20% of the violation amount (unless there is a justifiable reason); imprisonment and fine may be imposed together.
• Name disclosure (Framework Act on National Taxes Article 85-5): personal details and the violation amount can be published after review by the National Tax Information Committee.
• Where the person is punished under Article 16 or complies with a notification disposition, the Article 90(1) fine is not imposed (no double sanction).

How to use the calculator

Step 1: Enter the violation type and amount

Choose non-reporting or under-reporting, then enter the unreported amount (or the under-reported difference).
Non-reporting uses the full reportable balance; under-reporting uses the shortfall versus what should have been reported.

Step 2: Select the reporting year

Pick the year the accounts were held, and the deadline (30 June of the following year) is shown automatically.
The deadline is the reference date for the reduction brackets.

Step 3: Choose status and filing date

Indicate whether the case is still unreported/detected, or whether a voluntary amended/late filing was made.
For a voluntary filing, enter the filing date so the reduction rate is applied automatically.

Step 4: Review the result

See the total fine, the base fine, the reductions, and how much a voluntary filing saves.
Add the foreign-exchange report or an unexplained amount to reflect those factors.

Frequently asked questions

Q. If I lower the balance by year-end, can I skip reporting?

A. No.
The duty is judged by whether any month-end balance exceeded KRW 500 million, so a single month over the line triggers reporting.

Q. Is 10% of the balance not heavier than the tax itself?

A. The fine is an administrative sanction for breaching the reporting duty, not a tax.
Because it applies to the account balance, it grows with the amount — which is exactly why the voluntary-filing reduction matters.

Q. Is overseas real estate reportable here?

A. This regime covers financial accounts — bank, securities, derivatives, insurance, and virtual assets.
Overseas real estate is handled by a separate acquisition/holding/disposal reporting scheme, outside this calculator.

Q. Until when can I get the voluntary-filing reduction?

A. You must file before the authority imposes the fine and before you know it is coming.
Late filing has brackets up to 2 years and amended filing up to 4 years — the earlier, the higher the reduction.

Q. Does the result equal the actual fine?

A. This is a reference estimate under 2026 rules.
The actual fine can vary with the ±50% discretionary adjustment and individual facts, so consult a Korean tax professional for a specific case.

Check your fine now

Enter the unreported amount and the filing timing to see the fine and the reduction instantly.

A voluntary filing can cut the fine by up to 90% — the sooner, the better.

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