⚠️ Income Tax Penalty Calculator

Non-filing: tax payable x 20% (fraud 40%); double-entry obligor = max(tax x20%(40%), revenue x0.07%(0.14%)). Under-reporting: tax x 10% (fraud 40%); double-entry fraud = max(tax x40%, revenue x0.14%). Late payment: unpaid tax x days x 22/100,000 (0.022%/day, ~8.03%/yr, current since 2022-02-15). Excess refund: excess refund x 10% (fraud 40%). Days are counted from the day after the statutory due date to the actual payment date. For reference only; confirm on Hometax or with a tax agent.

⚠️ Based on the Framework Act on National Taxes of Korea

Non-filing and under-reporting penalties

Failing to file by the deadline triggers a non-filing penalty; reporting less than actual triggers an under-reporting penalty. Non-filing is 20% of tax payable (40% for fraud); under-reporting is 10% (40% for fraud). A double-entry obligor who fails to file by estimation faces the greater of the tax-based amount and revenue x 0.07% (0.14% for fraud).

How the late-payment penalty works

Unpaid tax accrues a late-payment penalty of 22/100,000 (0.022%) per day, roughly 8.03% per year, counted from the day after the due date to the actual payment date. For example, paying 10 million KRW 100 days late incurs 10,000,000 x 100 x 0.00022 = 220,000 KRW.

Reducing penalties

Filing late as soon as possible reduces the non-filing penalty: 50% off within 1 month of the deadline, 30% within 3 months, 20% within 6 months. Amended returns similarly reduce the under-reporting penalty. The late-payment penalty, however, keeps accruing until paid.