Delinquent tax rates for 2026 (Reiwa 8): 2.8% a year within two months, 9.1% a year after thatForgetting to pay tax adds "interest", and it gets higher after two months
If a national tax is not paid in full by the statutory due date, delinquent tax is charged for the number of days from the day after the statutory due date until the payment date. The rates for 2026 (Reiwa 8) are 2.8% a year up to the day two months after the day following the due date, and 9.1% a year after that. It applies to the base tax only, not to additional taxes (penalty taxes).
Key points
- It is charged when the tax is not paid in full by the statutory due date, when tax is due on a late return or an amended return, or when tax is due under a reassessment or determination.
- The rates for 2026 (Reiwa 8) are 2.8% a year until two months have passed and 9.1% a year after two months (as shown on the NTA page).
- The former is the lower of 7.3% and the delinquent tax special base rate + 1%; the latter is the lower of 14.6% and the delinquent tax special base rate + 7.3%.
- Delinquent tax applies only to the base tax, not to additional taxes and the like.
- In certain cases (for example an amended return filed after one year has passed since a timely return), a special rule excludes part of the period from the calculation.
What to do in practice
- If a payment is likely to be late, pay early because delinquent tax builds up by the day, or consult the collection section of the tax office.
- If an amended return becomes necessary, file and pay promptly, bearing in mind that the filing date becomes the due date.
If you miss the day to pay tax, extra money called "delinquent tax", a bit like interest, is added for each day you are late. In 2026 (Reiwa 8) the rate is 2.8% a year for the first two months of lateness and 9.1% a year after that, so the longer you wait, the heavier it gets.
Points
- If you pass the payment day, delinquent tax is added automatically according to the number of days you are late.
- Up to two months late, the rate is 2.8% a year; after two months, it goes up to 9.1% a year.
- It applies only to the original tax. It is not charged on top of penalty taxes (additional taxes).
What the words mean
- Delinquent tax
- Extra money, like interest, added by the number of days when a tax payment is late.
- Due date
- The last day by which a tax has to be paid.
- National Tax Agency (NTA): NTA: No. 9205 About delinquent tax
This article summarizes and explains materials published by government agencies and is not advice on any individual case. Rules can change, so for actual procedures and decisions always check the latest original materials and consult professionals such as tax accountants or labor and social security attorneys. English, Simplified Chinese and Traditional Chinese versions are translations prepared from the Japanese articles for convenience. If anything differs, the Japanese text and the original source take precedence.