Filing Taxes Online (e-Tax) in Japan: A Guide for Expats

Filing your Japanese tax return online with e-Tax can save you time, trips to the tax office and even help you avoid mistakes. This guide explains in English how to use e-Tax with your My Number card, what you need to prepare, and each step of the process.

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Table of Contents

What is e-Tax in Japan?

e-Tax is the Japanese National Tax Agency’s official online system for filing and paying national taxes such as income tax.

Instead of filling in paper forms and going to the tax office, you can:

Prepare your return in the Tax Return Preparation Corner on the NTA website.
Send it electronically using e-Tax.
Pay any tax due or receive a refund in your bank account.

For foreign residents, the NTA even publishes a multilingual manual called “You can create a Final Tax Return at Home!” that explains how to use the online Tax Return Preparation Corner.

If you are new to Japanese taxes overall, you may also want to read Tax basics for foreign residents in Japan and Double taxation in Japan.

Filing Taxes Online (e-Tax) in Japan: Step-by-Step Guide

Who actually needs to file a tax return?

In Japan, the tax year is the calendar year: 1 January to 31 December.

You normally need to file an income tax final return (kakutei shinkoku) if:

You are self-employed or a freelancer.
You have more than one employer.
You have side income (for example, part-time work, online sales or investment income) above certain thresholds.
You want to claim deductions that were not handled in year-end adjustment (nenmatsu chousei), such as large medical expenses or furusato nozei donations.

The National Tax Agency has an English page “Final tax return” that lists who must file and who can get a refund.

If you are a regular company employee with only one employer and no special deductions, you might not need to file, because your company does year-end adjustment for you.

Key dates and deadlines for e-Tax

For most individual income tax returns:

Filing period: usually 16 February to 15 March of the year after the income year.
If 16 February or 15 March is a weekend or holiday, the deadline moves to the next working day.

You can also file refund returns earlier (before 16 February) if you are due a refund.

Because e-Tax and the Tax Return Preparation Corner are available online (often 24 hours during the filing period), you can avoid queues at the tax office.

If you want to plan your cash flow and avoid surprises, see Budgeting and saving tips in Japan.

Why use e-Tax instead of paper filing?

Using e-Tax has several advantages, especially for busy foreign residents:

No paper forms – everything is entered online and automatically calculated.
Fewer mistakes – the system checks your numbers and warns about missing fields.
Faster refunds – refunds from e-Tax are often paid earlier than paper returns.
You can file from home using a smartphone, tablet or computer.

Japan is also moving strongly toward My Number card + smartphone as the standard way to log in and sign your tax return online.

What you need before using e-Tax

1. My Number and My Number card

To use e-Tax fully online, you almost always need:

Your My Number (12-digit Individual Number).
A My Number Card (plastic card with IC chip and your photo).

The card holds two important digital certificates:

A 4-digit PIN (user identification certificate) used to log in.
A 6–16 character password (signature certificate) used to sign and send your return.

If you do not yet have a My Number Card, you need to apply through the Digital Agency’s official channels or at your city office.

2. A compatible smartphone and the Mynaportal app

To read your My Number Card with your phone, you need:

An NFC-capable smartphone that supports My Number card reading.
The official Mynaportal app, available for Android and iOS.

From 2025, you can even add your My Number card to Apple Wallet on supported iPhones using the Mynaportal app, which makes login and signing easier.

On some Android and iPhone models, you can also use a “smartphone electronic certificate” that lets you authenticate without tapping the physical card every time.

3. A computer or tablet (optional)

You can file completely from your smartphone, but many people prefer a bigger screen. If you use a computer:

You still need a My Number card reader or a compatible smartphone acting as a reader.

4. Your tax documents

Before you start, collect:

Withholding slips (gensen choshuhyo) from each employer.
Income details from freelancing, rental, side jobs or overseas income.
Statements for insurance premiums, pension, mortgage and other deductions.
Receipts or certificates for furusato nozei or other donation deductions.
Your bank account details for receiving refunds (name in katakana, bank code, branch, account number).

If you are sending money abroad or receiving foreign income, check Double taxation in Japan so you understand how foreign tax credits work.

5. e-Tax login method

There are two main ways individual taxpayers log in to e-Tax:

My Number card method (マイナンバーカード方式) – recommended and now the standard.
ID/Password method (ID・パスワード方式) – available only if you received an ID and password from the tax office in the past.

From October 2025, tax offices have stopped issuing new ID/password credentials, so new e-Tax users must use the My Number card method. Existing ID/password users can still log in for now, but this method is considered temporary.

Overview: e-Tax vs other filing methods

Method	Where you file	Main advantages	Main drawbacks	Good for
e-Tax (online)	From home via PC or smartphone	No paper, auto-calculation, faster refunds, 24/7 access during period	Needs My Number card and some Japanese	Most residents comfortable with apps
Tax Return Preparation Corner + print	Online then submit by mail or at tax office	Easier data entry than hand-writing; can still submit on paper	Must print and physically submit	People without My Number card yet
Paper form at tax office	Local tax office counter	Can ask questions directly to staff	Long waits during busy season, manual calculation	First-timers with complex cases

For a smoother experience, many foreign residents start with e-Tax plus the foreigner input manual, and use the tax office only if they have special questions.

Step-by-step: Filing taxes online with e-Tax on a smartphone

This section follows the My Number card method, which is now the main recommended way to file online.

Step 1 – Check your My Number card and passwords

Before the busy season:

Confirm your My Number card is not expired, especially the electronic certificate (valid for 5 years).
Make sure you know your 4-digit PIN and 6–16 character password. If they are locked or forgotten, you must reset them at your city office.

Step 2 – Install and test the Mynaportal app

Install the Mynaportal app from the official store.
Open the app and test reading your My Number card with your phone’s NFC.
If your smartphone supports it, you can also set up a smartphone electronic certificate or, on supported iPhones, add your card to Apple Wallet for easier login.

Step 3 – Access the Tax Return Preparation Corner

During the filing season:

Go to the National Tax Agency’s special page for the current year’s tax return and open the Tax Return Preparation Corner.
Choose the smartphone option and select “Start”.
When asked how you want to submit, select “e-Tax (My Number card method)”.

If you feel nervous about the Japanese screens, open the foreigner manual “You can create a Final Tax Return at Home!” in English on another device and follow the screenshots.

Step 4 – Log in with your My Number card

The system will guide you to log in via Mynaportal:

When the tax site asks you to authenticate, it will switch to the Mynaportal app.
Follow the instructions to:
- Hold your My Number card to the back of your phone.
- Enter your 4-digit PIN when requested.
Once authenticated, the browser returns to the tax site, and you are logged in.

If you use a smartphone certificate or Apple Wallet, the steps may be even shorter, sometimes using your phone’s biometric login instead of entering the PIN every time.

Step 5 – Enter your basic information

The system will ask for:

Your name (in kanji or roman letters) and furigana.
Address and postcode.
Date of birth, occupation and phone number.
Your tax office (automatically selected by address in many cases).

The English foreigner manual shows the meaning of each field with screenshots, which is very helpful if you do not read Japanese well.

Step 6 – Import data with Mynaportal (optional but recommended)

One of the biggest advantages of e-Tax is Mynaportal linking:

You can have the system automatically pull data such as:
- Salary information from your employer’s e-withholding slip.
- Deduction certificates from life insurance companies, pension funds and others.
These items are then auto-filled into your tax return.

If you set this up, you will spend less time typing and reduce the risk of typing mistakes.

Step 7 – Enter your income

Next you choose the type of income to declare. Common choices for foreign residents:

Employment income (salary) – usually already withheld at source.
Business or self-employment income – for freelancers, sole traders or side jobs.
Real estate income – if you rent out property.
Miscellaneous income – for small side jobs, online sales or occasional work.

Screen by screen, you will:

Input totals from your withholding slips.
Enter your business income and expenses if you are self-employed.
Enter any overseas income in yen using appropriate exchange rates (NTA guides and foreigner tax articles explain how).

For complex situations (multiple countries, stock options, large investments), it is a good idea to check Double taxation in Japan or consult a tax advisor.

Step 8 – Enter deductions and tax credits

You then enter deductions, such as:

Social insurance premiums (health insurance, pension).
Private life or earthquake insurance premiums.
Medical expenses above the threshold.
Donations (including furusato nozei).
Spouse and dependent deductions, if applicable.

The NTA English income tax guide has detailed sections on each deduction category and examples of how to fill them in.

Step 9 – Check your calculated tax and refund

The system automatically calculates:

Your taxable income after deductions.
The income tax and special reconstruction tax you owe.
Any refund due because of excess withholding or deductions.

At this stage, carefully:

Review each screen.
Correct any obvious mistakes.
Print or save a PDF copy of the summary for your records.

Step 10 – Choose payment or refund method

If you owe tax, you can usually pay by:

Account transfer (direct debit) from your bank account – strongly recommended by the NTA and widely used.
Internet banking.
Credit card via the National Tax credit card payment site.
Convenience store using QR or barcode, depending on the amount and type of tax.

If you are due a refund, you enter your bank account so the tax office can transfer the money. The English income tax guides explain how to register a “public money receiving account”.

For more on bank accounts, see Best banks in Japan for foreigners and Opening a bank account in Japan

Step 11 – Sign and send your return via e-Tax

Finally, you send your return online:

The system asks you to apply an electronic signature using your My Number card.
You enter your signature certificate password (6–16 characters).
The return is transmitted to the NTA via e-Tax.

When it is complete, you will see a confirmation screen and can download a receipt or data file. Keep this in case of questions later.

Step-by-step: Using e-Tax on a computer

Using a computer is similar, but the screens are wider and sometimes easier to read.

You have two common setups:

PC + My Number card + card reader
PC + My Number card + smartphone acting as card reader

According to the NTA, if your smartphone can read the My Number card, you can use it as a card reader for a PC by connecting through specific steps explained in their smartphone-as-reader manual.

The overall flow is:

Access the Tax Return Preparation Corner on your PC browser.
Choose “e-Tax (My Number card method)” as the submission method.
When prompted, either:
- Insert your My Number card into the IC card reader, or
- Follow the instructions to read the card via your smartphone.
Log in, enter income and deductions, choose payment/refund options and sign, just like on a smartphone.

If you already have an ID/password and are used to that method, you can still choose it for now, but the NTA strongly recommends moving to the My Number card method.

Using e-Tax with ID and password (existing users only)

Some taxpayers received an e-Tax ID and password from the tax office in past years after an in-person identity check. This is called the ID/Password method.

Key points:

It is a temporary method designed to bridge the time until My Number cards became common.
From October 2025, tax offices no longer issue new IDs and passwords. New e-Tax users must use the My Number card method.
If you already have an ID/password, you can continue to use it for now, but some functions are limited compared with My Number card login.

If you are planning to stay in Japan, it is wise to move to the My Number card method soon.

Paying your tax or receiving a refund after e-Tax

Once your return is submitted:

If you owe tax, you must pay by the deadline (usually 15 March). Late payment triggers penalties and interest.
The NTA recommends account transfer (direct debit) for sole proprietors and individuals who pay every year, because it is convenient and automatic.
You can also use credit card payment via the National Tax credit card site, which is accessible from the NTA website.

If you are abroad when you need to pay, the NTA provides special guidance for taxpayers overseas, including options for credit card or overseas remittance.

If you are due a refund, the money is transferred to the bank account you specified in the return. Refunds via e-Tax tend to arrive faster than paper returns.

Common mistakes when filing taxes online in Japan

Even with e-Tax, there are traps to avoid:

1. Starting too late

The NTA and many tax guides warn that the lines at tax offices and phone support get very long in early March.

Start early so you can:

Reset My Number card passwords if needed.
Ask questions at the tax office or through English help lines.

2. Forgetting to prepare My Number and PINs

If you sit down to file but your card is expired, or you do not know your PIN and password, you will have to visit the city office to reset them.

Check these at least a few weeks before you file.

3. Not keeping proof and data

By law, taxpayers often need to keep records and supporting documents for several years (for example, seven years for many business records).

Even if you file online, always:

Save a PDF or printed copy of your final return and receipt.
Keep important receipts and certificates organised in a folder.

4. Ignoring local inhabitant tax

Your national income tax return also affects your resident tax (juminzei). After you file:

Your municipality uses your return to calculate your resident tax.
You will receive a notice in early summer, and your employer usually adjusts payroll accordingly.

If your income changes a lot, be prepared for changes in resident tax too. Cost of living in Japan and Negotiating salaries in Japan can help you understand the impact.

5. Misunderstanding foreign income and tax credits

If you earn income or pay tax overseas, you may need to use the foreign tax credit system to avoid double taxation.

This area can be complex, so combine this guide with Double taxation in Japan and consider talking to a tax professional.

When you should get help

e-Tax is powerful, but it does not replace professional advice. You should get help if:

You have high business or investment income.
You have multiple countries involved (salary abroad, foreign property, stock compensation).
You are selling real estate or company shares.
You receive letters from the tax office that you do not fully understand.

Sources of help include:

The NTA’s English guides for income tax and e-Tax.
Tax office consultation counters during the filing season (some larger offices can help in English).
Certified public tax accountants (zeirishi) who specialise in helping foreign residents.

Final tips for using e-Tax confidently

Filing taxes online in Japan does not have to be stressful. To keep it simple:

Make a checklist of documents you need and collect them early.
Confirm your My Number card, PINs and Mynaportal app are all working before the filing period.
Use the foreign language manual “You can create a Final Tax Return at Home!” alongside the Japanese screens.
File as early as you reasonably can, instead of waiting for mid-March.

Combine this article with other “Japan Handbook” guides like Tax basics for foreign residents in Japan, Double taxation in Japan, Best banks in Japan for foreigners to build a complete, stress-free plan for handling your money and taxes while you live in Japan.

This guide is for general information only. Tax rules change, and everyone’s situation is different, so always check the latest information on the National Tax Agency website or speak with a qualified tax professional before you file.

Disclaimer

This article is for general informational purposes only and does not constitute professional advice. Laws, prices and regulations vary by location and change over time. Consult a qualified professional for guidance on your specific situation.

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