- October 28, 2026
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If you want to file taxes online in Japan but feel uneasy about reading your My Number Card or entering a PIN, you’re not alone — plenty of foreign employees feel the same. The good news: a tax return doesn’t have to be on paper. You can file from your phone through e-Tax.
In this guide, certified financial planner Masamichi Takayanagi walks through just the practical steps — what you need, how to submit, how it works on your phone, and what to check after sending. For the bigger picture, like whether you need to file at all, see our existing guide, Income Tax Return in Japan.
About the Supervisor & Writer
Masamichi Takayanagi
Financial Planner & columnist;
An independent financial planner with extensive experience as a financial columnist, specializing in a wide range of topics including asset management, life insurance, inheritance, loan products, and credit cards. Over 1,000 articles and projects have been contributed to the field.
1st grade Certified Skilled Professional of Financial Planning, Certified Financial Planner®.
Table of Contents
Chapter 1: What to Get Ready Before You Start
To use e-Tax on your phone, start by preparing these three things:
- Your My Number Card
- A smartphone that can read the My Number Card
- The documents you need to file, such as your withholding slip and deduction certificates
With the My Number Card, you’ll mainly use two PINs: a four-digit “user certification PIN” (riyosha shomei), mainly for logging in, and a six-to-sixteen-character “signature PIN” (shomei-yo) for your electronic signature. Partway through, you may also be asked for the four-digit “card-surface input support” PIN, so it helps to have that ready too.
The user certification PIN locks after three wrong tries in a row; the signature PIN, after five.
If you’re a foreign national with a set period of stay, keep an eye on your My Number Card’s expiry date too. When you renew your period of stay, your card may need updating as well.
Use a phone that meets the National Tax Agency’s recommended environment. From August 2026, the “Mynaportal app” was renamed the “Myna app,” so update to the latest version.
Your filing documents might include:
- Your withholding slip for employment income (gensen choshu hyo)
- Deduction certificates for life insurance, iDeCo, and the like
- Donation receipts for furusato nozei (hometown tax)
- Medical expense notices or receipts
For the medical expense deduction, you generally prepare a medical expense deduction statement rather than submitting the receipts themselves. If you prepare the statement from your receipts, keep those receipts for five years.
Chapter2 : The Three Ways to File, in Brief
There are broadly three ways to submit a tax return:
- My Number Card method: verify your identity with the card and send through e-Tax.
- ID and password method: send through e-Tax using an ID and password already issued to you.
- Paper filing: print the return you’ve prepared and submit it by post or similar.
Strictly speaking, the third — paper filing — isn’t e-Tax.
If this is your first time using e-Tax, the My Number Card method is the standard choice. New issuance of the ID and password method stopped on October 1, 2025, so for now it’s generally limited to people who already registered for it.
You can file on paper even without a My Number Card. That said, a refund return that usually takes around one to one and a half months is processed in about three weeks through e-Tax, according to the National Tax Agency.
You file from your phone using the National Tax Agency’s online return-preparation tool, the Kakutei Shinkoku-sho tou Sakusei Corner.
The rough flow is these five steps:
- Go to the return-preparation tool.
- Select income tax, then choose the My Number Card method.
- Verify your identity with your My Number Card.
- Enter your income and deductions.
- Review the details and send through e-Tax.
On a phone, use the browser the National Tax Agency recommends. If the screen won’t advance, checking first whether your browser and OS meet the recommended environment makes it easier to narrow down the cause.
If you’re using a physical My Number Card, you enter your four-digit PIN and the like, then hold the card to your phone following the on-screen prompts.
On supported devices, there’s also the option of adding the My Number Card function to your smartphone itself. On iPhone, “My Number Card on iPhone” launched in June 2025, and the return-preparation tool began supporting it for the fiscal 2025 filing.
If you’ve added the card function to your phone, you may be able to proceed with face or fingerprint authentication instead of reading the physical card each time.
Enter your income and deductions by following the on-screen questions. If you set up My Number Portal (Myna) linkage in advance, you can pull in and auto-fill supported data — your withholding slip for employment income, medical expenses, furusato nozei, life insurance, iDeCo, and more.
That said, not all data can always be retrieved. A withholding slip, for example, depends on conditions such as your employer having submitted the relevant data through e-Tax.
Finally, check what you’ve entered and send it by following the on-screen prompts. If you’ve completed identity verification in advance on your e-Tax My Page, you can skip adding an electronic signature each time you send your filing data.
Chapter4 : What to Do After Sending
Even after you’ve sent your return through e-Tax, check these three things:
- Check the receipt notice
- Check your payment or refund
- Save a copy of your return and your input data
Once the submission is complete, a receipt notice arrives in your e-Tax message box. It shows the date and time received, the receipt number, and the tax office it went to, so it’s reassuring to save it as a record that your filing data reached the office.
If you have tax to pay, you pay it yourself by the deadline. The options include direct payment (direct debit), credit card, and smartphone app payment, each with its own conditions. Direct payment needs registration in advance, for example, and smartphone app payment is generally for amounts of 300,000 yen or less.
For a refund, the money is transferred to the account you specified when you filed. A refund return through e-Tax takes around three weeks as a guide, though it can run longer if there are missing documents or an amended return.
Save the PDF of your return, along with the input data you can use to prepare next year’s filing.
Chapter5 : When It Doesn’t Go Smoothly
If the card won’t read, start by checking these points:
- Whether your OS and browser meet the recommended environment
- Whether the Myna app is the latest version
- Whether your phone supports using the My Number Card
If a PIN gets locked and you still know either the signature PIN or the user certification PIN, you may be able to reset the other one at a convenience-store kiosk terminal, after completing a preliminary step on your phone. If you’ve forgotten both, handle it at your municipal office counter.
For e-Tax operations or errors, you can get help from the e-Tax and Return-Preparation Corner Help Desk.
Phone: 0570-01-5901
Hours: weekdays 9:00–17:00
For general questions about what to file or about tax itself, there’s the National Tax Consultation Line.
Phone: 0570-00-5901
Hours: weekdays 8:30–17:00
During the filing season, in-person consultation venues are also set up. If your tax situation is complex — income earned abroad, for example — separate the how-to-operate questions from the tax-judgment questions, and check with your tax office or a tax accountant as needed.
Source: National Tax Agency, e-Tax contact information (Japanese)
Chapter6 : Frequently Asked Questions
Q1: Can I use e-Tax without a My Number Card?
If you’ve already registered for the ID and password method, you can still use it. But since new ID and password issuance stopped on October 1, 2025, the My Number Card method is the standard choice for first-time users. Without a card, you can also prepare your return in the preparation tool, print it, and submit it by post or similar.
Q2: Can I complete everything on just my phone?
For many common filings — employment income, the medical expense deduction, furusato nozei, and so on — you can prepare and send from your phone. Supported models and operating systems get updated, so don’t go by “iPhone X or later” and the like; check the latest supported environment that the National Tax Agency and the Digital Agency publish.
Q3: By when do I need to file?
The filing deadline for 2026 income tax is March 15, 2027. Filing consultations and the acceptance of returns at tax offices begin on February 16, 2027. Refund returns can be filed from January of the following year, without waiting for the regular filing period. Deadlines and acceptance periods can change from year to year, so check the latest details in the National Tax Agency’s “Final Return Special Feature” for the year you’re filing.
Chapter7 : In Closing
If you have a My Number Card and a compatible phone, you can file your Japanese tax return from home through e-Tax.
Checking your card’s expiry date, your PINs, and your documents — withholding slip, deduction certificates, and the like — in advance makes the process go more smoothly.
For first-time e-Tax users, the My Number Card method is the standard choice. Follow the preparation tool’s prompts through identity verification, entering your income and deductions, reviewing, and sending.
After you send, check the receipt notice, handle your payment or refund, and save your filing data. If you get stuck on the operation, use the official help lines; if a tax judgment is involved, checking with your tax office or a professional is the reassuring route.
*This article is for general information only and is not individual tax advice. Information is accurate as of October 2026, but e-Tax screens, the app, supported devices, filing deadlines, and contact details change regularly, and each person’s filing situation is different. For your own case, check the latest details on the National Tax Agency’s site, and consider speaking with your tax office or a tax accountant before you file.
