If you live in Japan as a foreign resident, one of the most important administrative steps you will take is getting your My Number (tax number). This 12-digit individual number is used for taxes, social insurance, and a growing range of official procedures. Understanding how the My Number system works — and how to get yours — will save you a lot of confusion down the line. This guide walks you through the process clearly, step by step.
What Is My Number and Why Does It Matter for Foreign Residents?
My Number (マイナンバー) is Japan's national identification number system, introduced in 2016. Every resident in Japan — including foreign nationals — who is registered in the municipal resident registry receives a My Number. Think of it as your tax ID number in Japan.
You will need your My Number for:
- Filing your annual income tax return
- Enrolling in or using Japan's social insurance (health insurance, pension)
- Opening certain types of bank accounts or investment accounts
- Employment paperwork — your employer will ask for it
- Applying for government benefits or subsidies
In short, if you plan to live and work in Japan long-term, your My Number tax number is not optional — it is essential.
Who Is Eligible to Receive a My Number?
Any foreign national who is registered as a resident at their local municipal office (city hall or ward office) is eligible. This includes people on work visas, student visas, spouse visas, and other medium-to-long-term residence statuses. Short-term visitors (tourist visa, under 3 months) are generally not registered as residents and therefore do not receive a My Number.
If you have recently arrived in Japan and completed your address registration, your My Number notification should follow automatically — you do not usually need to apply separately.
How My Number Is Delivered: The Notification Letter
After you register your address at your local municipal office, the government will send a notification card (通知カード, tsūchi kādo) or a notification letter to your registered address by postal mail. This letter contains your 12-digit My Number.
Important points to know:
- The letter is sent by registered mail and requires a signature on delivery.
- If you miss the delivery, collect it from your local post office within the holding period (usually about one week).
- Make sure your name plate (表札, hyōsatsu) on your door or mailbox matches your registered name, as the postman needs to confirm the address.
- Keep your notification letter or card somewhere safe — you will need the number repeatedly.
Step-by-Step: What to Do After You Arrive in Japan
Step 1 — Register Your Address
Within 14 days of moving into your residence, go to your local city hall or ward office and complete your resident registration (転入届, ten'nyū todoke). Bring your passport and your residence card (在留カード, zairyū kādo). This is the trigger that starts the My Number process.
Step 2 — Wait for the Notification Letter
After registration, your My Number notification will be mailed to your address. This typically takes a few weeks, though timing can vary by municipality. Be patient and make sure someone is available to receive registered mail.
Step 3 — Confirm Your Number
Once you receive the letter, note down your 12-digit My Number carefully. The notification card (if you received one) is not an ID card on its own, but it shows your number.
Step 4 — Consider Applying for the My Number Card
Separately from the notification, you can apply for a physical My Number Card (マイナンバーカード). This is a plastic ID card with your photo and your My Number on it. It is optional, but increasingly useful. It can serve as a photo ID, allows access to online government services (マイナポータル), and is accepted at some banks and employers in place of other documents.
To apply for the My Number Card, you can:
- Apply online via the QR code printed on your notification letter
- Apply at your local municipal office in person
- Apply by post using the application form included with your notification
After applying, you will be called to your municipal office to pick up the card in person (bring your notification, passport, and residence card). Processing time varies — confirm the current timeline with your local office, as it can range from a few weeks to longer during busy periods.
Documents You Will Need
| Purpose | Documents Required |
|---|---|
| Resident registration (address registration) | Passport, residence card (zairyū kādo) |
| Applying for My Number Card | Notification letter (or QR code), passport, residence card, passport-style photo (if applying in person) |
| Picking up My Number Card | Notification letter, passport, residence card, PIN set in advance |
Common Worries — Answered
"I missed the postal delivery. What do I do?"
Go to the post office listed on the missed-delivery notice within the holding period (usually around 7 days). Bring your ID. If you miss this window, contact your local municipal office — they can reissue the notification.
"My employer is asking for my My Number but I haven't received it yet."
Let your employer know the notification is in the mail. Most employers understand the timing issue. Once you receive it, provide the number promptly. Your employer needs it for tax and social insurance filings.
"Is it safe to share my My Number?"
Yes — within the official contexts listed by the government (tax, insurance, employment). Be cautious about sharing it outside these official purposes. The Japanese government has strict laws governing how My Number may be used and stored.
"What if I move to a new address?"
You must re-register your address at your new municipal office within 14 days of moving. Your My Number stays the same, but update your registered address to ensure official mail reaches you.
My Number and Everyday Life in Japan
Once you have your My Number, several everyday processes become easier. When opening a bank account (such as at Japan Post Bank / Yucho, or other Japanese banks), you may be asked to provide it for tax reporting purposes. If you use international money transfer services such as Wise or Remitly to send money home, having your tax number in order means your financial records in Japan are properly organised. Your employer will use your My Number to report your income to the tax office each year.
Summary: Getting Your My Number as a Foreign Resident
Getting your My Number tax number as a foreign resident in Japan is straightforward once you know the steps. Register your address at your local municipal office as soon as you move in, wait for the notification letter to arrive by post, keep the number safe, and consider applying for the physical My Number Card for added convenience. Always confirm the latest procedures and timelines with your local municipal office or the official My Number Portal, as details can change.
Starting this process early — ideally within your first two weeks in Japan — sets you up well for taxes, social insurance, banking, and employment. You've got this: one step at a time, and Japan's administrative system becomes much less intimidating.