Suspicious traffic detected on e-Tax; emergency maintenance leaves the system unavailablee-Tax, the system for sending tax returns online, is down
On November 4, 2026 (Reiwa 8), the National Tax Agency announced that it had detected suspicious traffic on e-Tax and was carrying out equipment maintenance in order to investigate. e-Tax cannot be used while the maintenance continues. The agency says the end of the maintenance period will be announced separately on its website, and no date or time was given at the time of the notice. The notice carries an addition made at 19:00 the same day. Nothing is stated about how filing or payment deadlines will be handled.
- November 4, 2026 (Reiwa 8)The National Tax Agency reports detecting suspicious traffic on e-Tax and carries out equipment maintenance to investigate. e-Tax cannot be used during this period
- November 4, 2026, 19:00An addition was made to the notice
- End of the maintenanceTo be announced separately on the website; not given at the time of the notice
Key points
- The National Tax Agency says it detected suspicious traffic on e-Tax and is carrying out equipment maintenance in order to investigate
- e-Tax cannot be used while the maintenance continues
- The end of the maintenance period is to be announced separately on the website; no date or time was given at the time of the notice
- The notice was posted on November 4, 2026, with an addition made at 19:00 the same day
- The notice says nothing about how filing or payment deadlines will be handled
What to do in practice
- Before carrying out any electronic filing or payment planned for this period, confirm in the National Tax Agency's e-Tax notices that service has been restored
- If a filing or payment deadline is close, also consider routes that do not use e-Tax, such as filing on paper or paying at a counter
- Once service is restored, check that the receipt notices for filings and applications sent before the outage have arrived
When a company or an individual files a tax return, there is a system called e-Tax that lets them send it over the internet instead of carrying paper to the tax office. On November 4 the National Tax Agency said it had found suspicious traffic on e-Tax and was checking the equipment. Nobody can use e-Tax while that check goes on. The agency has not decided when it will finish, and says it will post the news on its website once it knows.
- 1. What was foundOn November 4, suspicious traffic was found on e-Tax
- 2. What the agency didIt began checking the equipment and made e-Tax unavailable in the meantime
- 3. What comes nextThe agency says it will announce on its website when the check is finished
Points
- On November 4 the National Tax Agency said it had found suspicious traffic on e-Tax
- e-Tax cannot be used while the check goes on
- The finish time has not been decided, and the agency says it will post the news on its website
What the words mean
- e-Tax
- Japan's national system for filing and paying taxes over the internet
- maintenance
- Checking or repairing a machine or a system
- National Tax Agency (NTA): National Tax Agency, e-Tax: Notice of emergency maintenance
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.