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My Number for Foreigners: What It Is and Why You Need It | MyKyoten

This is not a theoretical risk. It is the single most common administrative failure pattern reported by foreign residents in Japan.

Last verified: 2026. This guide is based on Immigration Bureau regulations, Ministry of Health Labour and Welfare guidelines, and standard Japanese administrative practice. It is informational only and does not constitute legal advice. Consult a licensed immigration attorney or official government sources for case-specific guidance.

Most foreigners receive a thin envelope from their city hall within a few weeks of registering their address. They open it, see a paper card with a 12-digit number, and put it in a drawer. That decision creates problems that surface months later, sometimes at the worst possible moment: during year-end tax processing, during pension enrollment, or mid-application for permanent residency.

This is not a theoretical risk. It is the single most common administrative failure pattern reported by foreign residents in Japan.

So What Actually Is My Number, and How Do You Get It?

My Number (マイナンバー) is a 12-digit individual number assigned by the Japanese government to every person registered in the resident registry, including foreign nationals with mid-to-long-term residency status.

The trigger is simple. You complete your 転入届 (residence registration) at city hall after arriving in Japan. The system generates your number automatically. Approximately 2 to 3 weeks later, a sealed envelope arrives at the address you registered. Inside is your 通知カード (notification card), a plain paper or thin card document printed with your name, address, date of birth, and your 12-digit number.

The number itself never changes. Even if you move, renew your visa, change your name, or switch visa categories, your My Number stays the same for life.

Here is the part nobody tells you: the envelope is sent by registered mail requiring a signature, and if you are not home when delivery is attempted, it goes back to city hall. If the card is returned undelivered, you need to visit city hall in person with your residence card and request reissuance. Some offices hold returned cards for 3 months before treating them as abandoned. Do not assume the post office will hold it indefinitely.

If you received your number card but have lost it, you can use the My Number Notice Decoder to understand the reissuance documents you will receive from city hall.

→ Use the Document Decoder to translate and understand your Japanese administrative documents.

Notification Card vs. My Number Card: They Are Not the Same Thing

This is where people mess up constantly.

The 通知カード (notification card) is a paper document. It proves your number exists, but it cannot be used as photo ID. As of 2020, notification cards are no longer issued for new registrations and are technically no longer valid as proof of My Number for most official purposes under updated administrative guidelines. Many employers and financial institutions still accept it combined with a separate photo ID, but this varies.

The マイナンバーカード (My Number card) is a physical IC chip card with your photo. It functions as official photo ID, proof of your My Number, and increasingly as your health insurance certificate. It is the one card that does everything.

| Feature | Notification Card (通知カード) | My Number Card (マイナンバーカード) | |---|---|---| | Photo ID | No | Yes | | Proof of My Number | Limited / declining acceptance | Yes | | Health Insurance use | No | Yes (Maina Hoken) | | Online government services | No | Yes | | Still being issued | No (stopped 2020) | Yes | | Cost | Free | Free |

Upgrading is not optional anymore in practice. Banks, pension offices, and employers increasingly refuse the notification card alone. Get the My Number card.

For a detailed breakdown of how the two documents differ in 2026, see the Residence Card vs My Number 2026 guide.

Where You Are Legally Required to Provide Your My Number

Basically every institution that touches your money or your social insurance enrollment will ask for it.

Employer paperwork: When you start a job, you complete the 扶養控除等申告書 (Dependent Deduction Withholding Declaration). This form requires your My Number. Without it, your employer cannot process year-end tax adjustments correctly. Your withholding tax may be calculated at the higher non-declaration rate.

Pension enrollment: Both 厚生年金 (Employees' Pension Insurance) and 国民年金 (National Pension) require My Number for enrollment and contribution tracking. If your number is not linked, your contribution records may not connect properly when you later claim benefits or apply for a pension lump-sum refund. For a full breakdown of how pension enrollment works for foreign residents, see the pension and social insurance guide.

National Health Insurance: Your NHI enrollment at city hall requires your My Number. The Health Insurance Notice Decoder can help you read the notices you receive after enrollment.

Bank accounts: Under FATCA-linked and CRS regulations, Japanese banks now collect My Number when opening new accounts and are conducting retroactive collection campaigns for existing accounts. Refusing to provide it does not immediately close your account, but the bank is required to flag your account and may restrict services.

Tax return filing: If you file a 確定申告 (individual tax return), your My Number is required on the form. A submission without it may be accepted but flagged as incomplete, and the tax office can follow up.

Warning: Failing to provide My Number when legally required is a violation under the My Number Act. Providing a false number carries a penalty of up to 300,000 yen in fines. The practical enforcement risk for ordinary foreigners is low based on current administrative practice, but the legal exposure is real.

How to Actually Apply for the My Number Card

Step 1: Locate your 通知カード. On the back of the card (or the notification letter), find the QR code.

Step 2: Use a smartphone to scan the QR code. This takes you to the online application portal (マイナンバーカード総合サイト). Create an account using your email, then upload a photo of your face. The photo must be plain white background, no glasses, taken within 6 months.

Step 3: Submit the application. You will receive a confirmation email. Processing takes approximately 4 to 6 weeks currently, based on reports from foreign residents in major cities.

Step 4: City hall sends you a postcard notification when your card is ready. You must bring this postcard, your notification card, your residence card, and any other requested ID to pick up the card in person. Some city halls now require a prior appointment. The card cannot be picked up by someone else without a notarized proxy authorization.

Cost: The card itself is free. If you lose it and need reissuance, there is a reissuance fee of 1,000 yen for the card plus 500 yen for the electronic certificate, as of current fee schedules.

The alternative is in-person application at city hall. Bring your notification card, residence card, and a photo (4cm x 3cm, plain background). Staff will take your application at the counter.

[Step-by-Step Checklist] My Number Card Application

What Happens When You Move or Change Visa Status

Moving address is the step where foreign residents routinely let My Number administration fall apart.

When you move, you have 14 days to register your new address via 転入届 at city hall. That same visit is when you update your My Number card address. The address on the card is printed on a sticker that city hall staff attach to the back. Do not skip this.

If you do not update within 14 days, your My Number card becomes technically invalid as an ID document. Institutions that scan the IC chip will detect an address mismatch and may refuse to accept it. More critically, if your pension or tax records are still linked to the old address, correspondence and notices go to the wrong place. See the address change reporting guide and the missing 14-day address rule guide for exactly what the consequences look like in practice.

Changing visa status does not change your My Number. A Brazilian data analyst who changes from Engineer/Specialist in Humanities to Highly Skilled Professional visa keeps the same 12-digit number. However, you should confirm your resident registration was updated correctly after the status change, because errors at this step have been known to create duplicate or suspended records in local government systems, based on common experience reported by foreign residents.

What if you leave Japan temporarily for more than a year? If you deregister from the resident registry (転出届), your My Number record is suspended. When you return and re-register, the same number is typically reactivated. Do not assume it disappears permanently.

What if your notification card envelope was delivered to your old address because you moved before it arrived? Go to city hall in person immediately with your residence card. Explain the situation. They can trace whether the card was returned and reissue documentation from the counter.

Real Situation: What This Looks Like in Practice

A Vietnamese software engineer on a Highly Skilled Professional visa joined a Tokyo company in April. HR asked for My Number during onboarding. She provided her 12-digit number verbally but could not produce the physical notification card because she had lost the envelope. Her employer's payroll system flagged the entry as unverified.

By December, when year-end tax adjustment (年末調整) paperwork was distributed, her 扶養控除等申告書 was returned incomplete. Payroll processed her at the non-declaration withholding rate. She overpaid approximately 18,000 yen in income tax for that year, which she only recovered by filing a 確定申告 in February the following year and waiting 6 to 8 weeks for a refund deposit.

Had she applied for the My Number card in April, the card would have been in hand before the May pension enrollment deadline, the tax paperwork would have been clean, and the 18,000 yen would have stayed in her account.

If you are navigating payslip deductions and want to understand how your tax and pension figures appear on your pay documents, the Payslip Decoder can walk you through each line in plain language.

Your next step: Go to the drawer where you put that notification card envelope, find your 12-digit number, and if you have not already applied for the My Number card, scan the QR code on the notification card tonight and start the online application. If the card is missing, book a city hall appointment this week.

Can I use my residence card instead of My Number at the bank? No. Your residence card and My Number are separate documents serving different purposes. Banks need your My Number for tax reporting compliance under FATCA and CRS rules. Your residence card proves your identity, but it does not contain your My Number. You need both.

What if I work multiple jobs - do I submit My Number to each employer? Yes. Each employer who pays you salary must collect your My Number for tax withholding purposes. You submit a 扶養控除等申告書 to your main employer and a separate withholding form to secondary employers. Failing to provide it affects how each employer calculates your income tax deductions.

Does my My Number expire when my visa expires? No. Your My Number itself has no expiry. However, the electronic certificate on your My Number card expires every 5 years and must be renewed at city hall. The physical card is also linked to your residency status, so when your residence card is renewed, update your My Number card records at the same city hall visit.

If you received a tax-related notice tied to your My Number registration and cannot read what it is asking for, the Payslip Decoder is built to decode Japanese payroll and tax documents into plain English. Paste in or photograph your document and it will identify each field, what it means, and what action if any is required from you.