My Number and the My Number Card: What Residents Should Know

A friendly explanation of Japan's twelve-digit My Number and the optional IC card that turns it into identification, online access and a health insurance card.

Published October 20, 2026 at 3:17 PM JST | By Tokyo Paul

Quick answer: My Number is a 12-digit personal identification number that Japan assigns to residents, including foreign residents registered with a municipality. The My Number Card is an optional IC card that carries it, works as photo identification, and can be used for online procedures, convenience-store certificates and as a health insurance card. For adults the card is valid for ten years, and renewal is free.

If you live in Japan, you will hear about My Number sooner or later, usually at city hall, at a bank, at work, or at the clinic. The topic can sound technical, but the idea is friendly: one number that links your records for tax, social security and other official procedures, and one card that makes many tasks simpler. This guide explains the difference between the number and the card, how to apply, how long the card lasts, what it is used for, and how foreign residents can handle expiry dates and status renewals.

What is My Number?

My Number, officially the Individual Number, is a 12-digit number issued to people who live in Japan. Wikipedia describes it as a national identification number and notes that Japanese citizens and foreign residents who are registered in the resident register are eligible. It was introduced as part of a system for administrative procedures.

Japan's Digital Agency describes the My Number system as a way of identifying specific individuals in administrative procedures, so that agencies can coordinate information and the need for attached documents is reduced. Its examples include preparing tax returns and applying for pensions through the online portal called Mynaportal.

The number arrives on a notice sent to your registered address, usually after you complete move-in procedures at city hall. It is a long-term identifier, so keeping the notice safe is a good habit.

What is the My Number Card?

The My Number Card, officially the Individual Number Card, is an IC card that certifies your number. The government's official page explains that it is an identification card that also carries an electronic certificate, which allows identity verification for online administrative procedures and some private services.

The card has a photo, so it works as official identification in many everyday situations, from opening a bank account to picking up a package. It was first issued in January 2016, according to Wikipedia, and it is not mandatory to hold one. Many residents choose to get it because of the convenience.

Because the card is separate from the number itself, you can know your number without having the card, and you can have the card without carrying the notice around. The card is the practical tool, and the number is the underlying record.

How do you apply for a My Number Card?

Applications are made with the form that came with your Individual Number notice, which includes a QR code for online applications. You can apply online with a smartphone or computer, by mail, or at a photo booth that supports the service. Newcomers from overseas receive an application form with their notice.

After applying, the card is prepared and you are asked to visit your municipal office to receive it, and some offices require an appointment. Bring the notice from the municipality and identification documents as instructed. Setting your PIN codes happens at the counter.

The official guidance explains that foreign residents with a specified period of stay are told how to apply by their Regional Immigration Bureau when the number is issued. If you are not sure how to proceed, your city hall's resident counter can walk you through the steps.

How long is the card valid?

For adults who were 18 or older when the card was issued, the card is valid until the tenth birthday after issuance, and it is valid for five years for those who were younger. The electronic certificate, which allows online identity verification, is valid for five years regardless of age, according to the Digital Agency's page.

Renewal is free. You can renew from about three months before the expiry date at the office where you are registered, and a notice arrives two to three months before. The card's expiry date is printed on the front, and the electronic certificate date can be checked on Mynaportal.

If the electronic certificate expires and is not renewed, the card can still act as a health insurance card for a limited time, but online identification stops working. Putting the date in your calendar is an easy way to avoid surprises.

How does validity work for foreign residents?

For many foreign residents, the card is tied to the length of the period of stay. Inagi City's English guide explains that permanent residents, highly skilled professionals of the second type and special permanent residents follow the same validity as Japanese citizens, while other mid- to long-term residents have a card valid until their residence period ends.

When your residence period is renewed, the card needs to be updated too, and the guide notes that a card whose validity has expired can no longer be used. It also mentions a short extension if a renewal is pending when the stay period ends, so ask your office about the details.

Because rules can change, it is wise to check with your municipal office or the Immigration Services Agency whenever you renew your status. A quick visit after receiving a new residence card keeps everything aligned.

What can you do with the card?

The card is useful in several ways. It serves as identification, it supports online procedures on Mynaportal, and it can be used to obtain certificates such as a residence certificate at convenience-store kiosks, depending on your municipality. A driver's license integration also exists for people who want to combine the two cards at a license center.

One of the most common uses today is as a health insurance card. After registering the card for this purpose, you can use it at participating clinics and pharmacies. Japan stopped issuing new traditional health insurance cards, and a certificate of eligibility is the alternative for those without a registered card.

The card also holds several PINs, including four-digit numbers for the resident register and a longer password for electronic signatures. Choosing codes you can remember, and keeping them private, is part of using the card well.

What about the new combined residence card?

Japan has introduced an optional Specified Residence Card for foreign residents that combines the residence card and the My Number Card in one IC card. Law firm summaries explain that it is voluntary, and that it is offered while completing certain immigration procedures, such as an extension or a change of status.

Existing residence cards and My Number cards remain valid until their normal expiry dates, so there is no rush to change. People who do choose the combined card are generally required to appear in person for the procedure.

Because details are updated by the Immigration Services Agency, check its pages for the latest information if you are considering the option.

How should you keep your number and card safe?

Treat the number and the card like any important document. Keep them in a secure place, and share the number only with parties that have a proper reason, such as an employer completing tax and social security forms. If a card is lost, contact your municipal office promptly so that they can guide you on suspension and reissue.

When using Mynaportal or other online services, protect your PINs and avoid writing them on the card. Many residents find a password manager or a sealed note at home helpful.

A reissued card can carry a fee, and the official page notes that exceptions exist for certain disasters. Asking your office before you apply for a replacement is a simple way to understand the process.

Frequently Asked Questions

Is the My Number Card mandatory for foreign residents?

No. The My Number number is issued to registered residents, but holding the card is optional. Many residents apply for it because it works as photo identification, supports online procedures, and can be used as a health insurance card. Your municipal office can explain how to apply.

How long does a My Number Card last?

For adults, the card is valid for ten years, and for those under 18 at issuance, five years. The electronic certificate lasts five years. For many foreign residents, the card's validity follows the period of stay, so update it when your status is renewed.

Can the My Number Card be used as a health insurance card?

Yes, after registration. You can register it at a terminal at a medical institution or pharmacy, at some ATMs or through the online portal, and then use it at participating facilities. A certificate of eligibility is available as an alternative.

Keep Exploring

More guides from Tokyo Paul: National Health Insurance in Japan: How Residents Enroll and Use It, Moving to Japan: Residence Card, Address Registration and the First Visit to City Hall and Opening a Bank Account in Japan as a Foreign Resident.