Fake Japan Tax Agency Emails: How to Spot Them (Oct 2026)

How to tell: if any of these five appear, it is fake

Based on the NTA's "Beware of suspicious emails and phone calls" and e-Tax's "Beware of suspicious emails" and "If you received an email such as 'Notice from the tax office'".

The same applies to SMS (text messages). The NTA does not send SMS notices containing URLs, and never uses SMS, email or LINE to demand payment or announce a seizure[NTA, Beware of suspicious emails and phone calls (in Japanese)].

Genuine e-Tax emails come from one sender only, "e-Tax（国税電子申告・納税システム）<[email protected]>", and the subject is either 「税務署からのお知らせ」("Notice from the tax office") or 「国税庁からのお知らせ」("Notice from the National Tax Agency"). But fake emails also use the subject 「税務署からのお知らせ」 and disguise the display name as "e-Tax", so you cannot tell them apart by the subject and sender name alone. If you have registered a name, genuine emails address you by the name you registered. Greetings such as 「納税者様」("Dear taxpayer") or 「担当者様」("Dear person in charge") are a mark of fakes.

Subject lines seen in September–October 2026

Below, subject lines cited as examples by the NTA and the Council of Anti-Phishing Japan are listed separately from reports sent to a private scam-information site. Subject lines change constantly, so do not assume an email is genuine just because its subject is not listed here.

Subject lines cited by the NTA and the Council of Anti-Phishing Japan

The Council says "the above is only a small part; many other subject lines have been confirmed"[Council of Anti-Phishing Japan, 30 Sep 2026 (in Japanese)].

Subject lines reported to a private scam-information site (October)

From reports posted on Sagi Higai Navi (fraudnavi.com). Not confirmed by the NTA.

The "documents sent by post" type says in the email that "documents were sent via Japan Post" and steers you to log in to a Message Box or install an app. The "past-year refund claim" type writes in the body that "we never ask you to enter or reply with bank or card details" to lower your guard, and then places an app download button.

The deductions they name are the ones many people actually use: furusato nozei (hometown tax donations), the medical expense deduction, the housing loan credit and the spouse deduction. At this time of year, when people start preparing for year-end adjustment and tax returns, it is easy to believe "you have a refund". A genuine refund is simply paid into the account written on your return, after you have filed it yourself (explained below).

「税金控除申請に必要な書類送付について」("About sending documents needed to apply for tax deductions") is not a scam

More and more people are searching for this phrase, but it is an option you choose when applying for a donation on Rakuten Furusato Nozei[Rakuten Furusato Nozei, paper application for the one-stop exception (in Japanese)]. It lets you choose whether the municipality should send you paper documents.

Depending on the municipality, a receipt or application form may be sent whichever option you choose. Note that the one-stop exception becomes void if you file a tax return. The mechanism and the cap are explained in the tax-saving effect of furusato nozei and how to claim it, and how to fix things when it overlaps with a tax return in filing a tax return voids the whole one-stop exception.

How genuine contact from the tax office arrives

• Paper: as a rule, in an envelope printed with the name of the regional taxation bureau or tax office. If something arrives by courier and looks suspicious, check with the tax office's general affairs section.
• Phone: as a rule, to confirm with you the content of a return you have filed. If it seems suspicious, ask for the caller's department, name and phone number, hang up, and contact the tax office's general affairs section or the bureau's taxpayer support coordinator using the number on the NTA website. How to judge such calls, and how penalty taxes differ depending on whether it is an audit or administrative guidance, are covered in a call from the tax office.
• Refunds: paid into an account in your own name written on your return (collection at a Japan Post Bank or post office counter is also possible). Refund claims filed via e-Tax are processed in about three weeks. You can check the progress yourself with e-Tax's "refund processing status"[e-Tax, Check refund processing status (in Japanese)]. You will never be asked to operate an ATM.
• Payment: you choose and pay yourself by account transfer, direct payment, credit card, smartphone app, convenience store or at a counter. The NTA states that "after you submit your return, the tax office does not send payment slips or tax notices"[NTA, National tax payment procedures (in Japanese)].
• Email: email is used in tax audits and the like only if the taxpayer requests it. It is never sent without consent.

What to do if you opened it, entered details or paid

Based on the Council of Anti-Phishing Japan's "FAQ" and "Phishing reports", IPA, the National Consumer Affairs Center of Japan and e-Tax's "FAQ".

The National Consumer Affairs Center has received a consultation from a person in their 20s who sent money by code payment after an email said "if you do not pay within 24 hours, your assets will be seized"[National Consumer Affairs Center, 27 May 2026 (in Japanese)]. Real national tax arrears start with a demand letter or similar sent by post. The actual process from arrears to seizure is touched on in national tax arrears of ¥993.5 billion, over half of it consumption tax.

Summary

• In October 2026, most fake emails dangle documents or refunds, such as 「税務署より重要書類を発送」("the tax office has sent important documents") and 「過年分の還付申告 提出期限」("deadline for past-year refund claims")
• The goal is a fake Android "e-Tax app". The smartphone e-Tax app ended on 4 January 2021 and no longer exists
• A refund or arrears amount, an app installation, an attachment, or a URL in the body: if any of these appear, it is fake
• Even with the subject 「税務署からのお知らせ」("Notice from the tax office"), it can be fake. Do not click the link; log in to e-Tax yourself and check the Message Box
• 「税金控除申請に必要な書類送付について」 is an item on the Rakuten Furusato Nozei application screen, not a scam

Sources

• NTA, "Beware of suspicious emails and phone calls" (in Japanese)
• e-Tax, "Beware of suspicious emails posing as e-Tax" (updated 16 October 2026, in Japanese)
• e-Tax, "If you received an email such as 'Notice from the tax office'" (in Japanese)
• e-Tax, "About the e-Tax app" (in Japanese)
• NTA, "National tax payment procedures (G-2)" (in Japanese)
• e-Tax, "Check refund processing status" (in Japanese)
• National Consumer Affairs Center, "The NTA never asks you to pay tax by SMS or email!" (27 May 2026, in Japanese)
• Council of Anti-Phishing Japan, "Phishing emails posing as the NTA and leading to installation of malicious apps" (30 September 2026, in Japanese)
• Council of Anti-Phishing Japan, "FAQ" (in Japanese)
• IPA, Security consultation desk newsletter (in Japanese)
• Sagi Higai Navi, search results for "National Tax Agency" (private reports, in Japanese)
• Rakuten Furusato Nozei, "One-stop exception: how to apply on paper" (in Japanese)

This article is general information based on published materials and received-email reports as of 20 October 2026. If you are unsure whether an email is genuine, check with your nearest tax office, the police or a consumer affairs centre.