The core idea: a number the state gives you, a card you choose to carry
The official name of the number is kojin bangō (個人番号), literally 'individual number'; mainanbā, My Number, is its made-up English nickname. It has 12 digits and is used in social security, tax and disaster procedures. You do not apply for it. About two to three weeks after you register your address, a paper kojin bangō tsūchisho (個人番号通知書), number notice, arrives by registered post. Keep it, but know its limits: it is not ID and cannot prove your number.
The card, mainanbā kādo (マイナンバーカード), formally kojin bangō kādo, is something you apply for. It is a photo ID and the most convenient way to prove your number. Without it, a copy of your resident record showing the number does the same job. The table sets the family side by side.
| Item | Reading | What it is | How you get it |
|---|---|---|---|
| 個人番号 | kojin bangō | Your 12-digit number | Automatically, when you register an address |
| 個人番号通知書 | kojin bangō tsūchisho | Paper notice of the number; not ID | By registered post |
| 通知カード | tsūchi kādo | Older paper card, not issued since 25 May 2020 | Only if you received one before then |
| マイナンバーカード | mainanbā kādo | Plastic photo ID with a chip | You apply, then collect it at the city office |
| 特定在留カード | tokutei zairyū kādo | Residence card that is also a My Number card, since 14 June 2026 | Requested alongside an immigration or address procedure |
On your first day at a new job, someone from HR will ask for the number, because payroll and social insurance need it.
Applying for the card and collecting it
The application form comes in the same envelope as the number notice, with a QR code for applying by smartphone. You can also apply by computer, at some photo booths or by post, with a photo taken within the last six months. About a month later a postcard, the kōfu tsūchisho (交付通知書), literally 'handover notice', invites you to the city office; some offices require an appointment. Bring the postcard and your residence card as ID. The clerk checks your face against the photo, asks you to confirm the details and has you set your PINs.
| Japanese | Romaji | Meaning |
|---|---|---|
| 交付通知書が届いたので、受け取りに来ました。 | Kōfu tsūchisho ga todoita node, uketori ni kimashita. | My collection notice arrived, so I've come to pick up my card. |
| ご予約はされていますか。 | Goyoyaku wa sarete imasu ka. | Do you have an appointment? |
| 本人確認書類を拝見します。 | Honnin kakunin shorui o haiken shimasu. | I'll take a look at your ID. |
| お写真とご本人を確認させていただきます。 | Oshashin to gohonnin o kakunin sasete itadakimasu. | Let me check the photo against you. |
| 記載内容にお間違いはありませんか。 | Kisai naiyō ni omachigai wa arimasen ka. | Is everything on the card correct? |
| はい、大丈夫です。 | Hai, daijōbu desu. | Yes, it's all fine. |
What the card shows on each side
The front carries shimei, jūsho, seinengappi and seibetsu, the four items (yon jōhō) of name, address, date of birth and sex, with your photo and the line ... made yūkō, valid until. A separate box shows the denshi shōmeisho no yūkō kigen (電子証明書の有効期限), literally 'electronic certificate valid period', which ends earlier. The tsuikiran (追記欄), additions box, receives later changes such as a new address. The back carries the 12-digit number, your name and birth date, and the chip.
The two sides have different jobs. The front is a photo ID you can show at a bank, a phone shop or a hotel. The back is for number checks, which only certain organisations may make.
| Japanese | Romaji | Meaning |
|---|---|---|
| 本人確認書類はお持ちですか。 | Honnin kakunin shorui wa omochi desu ka. | Do you have proof of identity? |
| マイナンバーカードでいいですか。 | Mainanbā kādo de ii desu ka. | Is my My Number Card all right? |
| 表だけコピーさせていただきます。 | Omote dake kopī sasete itadakimasu. | We'll copy only the front. |
| 裏はコピーしないでいただけますか。 | Ura wa kopī shinaide itadakemasu ka. | Could you not copy the back, please? |
Four PINs and what each one unlocks
When you collect the card, the clerk asks you to set anshō bangō (暗証番号), PINs, on a form or a keypad. The chip holds two electronic certificates. The shomei-yō denshi shōmeisho (署名用電子証明書), literally 'certificate for signatures', signs online applications such as a tax return; its password is 6 to 16 characters and must mix capital letters and numbers. The riyōsha shōmei-yō denshi shōmeisho (利用者証明用電子証明書), literally 'certificate for proving the user', only confirms that you are you, with four digits.
Two more four-digit PINs protect the resident register function and the function that reads your number and four items into forms. The three short PINs may share one number, but avoid your birth date. At the counter, the clerk walks you through it.
| Japanese | Romaji | Meaning |
|---|---|---|
| 暗証番号を設定してください。 | Anshō bangō o settei shite kudasai. | Please set your PINs. |
| 4桁の数字を入力してください。 | Yon-keta no sūji o nyūryoku shite kudasai. | Please enter a four-digit number. |
| 3つとも同じ番号でもいいですか。 | Mittsu tomo onaji bangō demo ii desu ka. | Is it all right to use the same number for all three? |
| 英字は大文字でお願いします。 | Eiji wa ōmoji de onegai shimasu. | Please use capitals for the letters. |
Where you actually use it
Most uses fall into two groups: places that need the number, and places that need the chip. Your employer and a securities company need the number; a convenience store and a clinic need the chip and a PIN or your face. At a konbini multi-copy machine you can print jūminhyō no utsushi (住民票の写し), literally 'copy of the resident slip', the proof of address that landlords and employers ask for, if your municipality offers the service. Registering the card as your health insurance card, called maina hokenshō, lets clinics read your insurance status at a card reader. A newcomer asks a convenience-store clerk for help.
| Japanese | Romaji | Meaning |
|---|---|---|
| 住民票の写しをここで取れますか。 | Jūminhyō no utsushi o koko de toremasu ka. | Can I get a copy of my resident record here? |
| マルチコピー機はどちらですか。 | Maruchi kopīki wa dochira desu ka. | Where is the multi-copy machine? |
| カードを置いて、暗証番号を入れてください。 | Kādo o oite, anshō bangō o irete kudasai. | Place your card and enter your PIN. |
| Place | Reading | What you do there | What it needs |
|---|---|---|---|
| 勤務先 | kinmusaki | Give your number for payroll and social insurance | The number |
| コンビニ | konbini | Print a copy of your resident record | Chip and four-digit PIN |
| 病院・薬局 | byōin, yakkyoku | Show it as your health insurance card | Chip, then face or four-digit PIN |
| 市役所・区役所 | shiyakusho, kuyakusho | Moving, certificates, updating the card | Card and four-digit PINs |
| 証券会社・銀行 | shōken gaisha, ginkō | Investment accounts and overseas transfers | The number |
| マイナポータル | mainapōtaru | The government's online portal | Chip and four-digit PIN |
| e-Tax | ī-takkusu | Filing a tax return online | Chip and signing password |
The bank visit itself, and the forms with a box for your number, each have their own guide.
Beyond the basics: two expiry dates, and the extra step for foreign residents
The card and its certificates expire separately. A card issued at 18 or over lasts until the tenth birthday after issue, or the fifth for under-18s; the certificates last until the fifth birthday after issue at any age. A notice arrives two to three months before either runs out, and you renew at the city office from three months ahead.
Foreign residents with a period of stay have a third limit: the card expires on the last day of that period, or on the tenth birthday, whichever comes first. Immigration renewing your status does not update the card. After receiving your new residence card, go to the city office and ask for a yūkō kikan henkō (有効期間変更), change of validity period, before the old date. No reminder is sent for this. The Specified Residence Card is no exception: its My Number function also ends with your original expiry date. If you leave Japan for good, foreign nationals must return the card.
| Japanese | Romaji | Meaning |
|---|---|---|
| 在留期間が更新されたので、カードの有効期間を変更したいです。 | Zairyū kikan ga kōshin sareta node, kādo no yūkō kikan o henkō shitai desu. | My period of stay was extended, so I'd like to change the card's validity. |
| 新しい在留カードをお持ちですか。 | Atarashii zairyū kādo o omochi desu ka. | Do you have your new residence card? |
| 電子証明書の更新もお願いします。 | Denshi shōmeisho no kōshin mo onegai shimasu. | I'd like to renew the electronic certificates too. |
A lost card or a locked PIN
If the card is lost or stolen, call the 24-hour card helpline to suspend it at once, report the loss to the police, then apply for a new card at the city office. A locked PIN is fixed at the city office where you are registered; you bring the card and set a new one. Here are both situations, from your side and the clerk's.
| Japanese | Romaji | Meaning |
|---|---|---|
| マイナンバーカードをなくしてしまいました。 | Mainanbā kādo o nakushite shimaimashita. | I've lost my My Number Card. |
| カードを一時停止してください。 | Kādo o ichiji teishi shite kudasai. | Please suspend the card. |
| 警察には届けましたか。 | Keisatsu ni wa todokemashita ka. | Have you reported it to the police? |
| 暗証番号を忘れてしまいました。 | Anshō bangō o wasurete shimaimashita. | I've forgotten my PIN. |
| ロックがかかってしまいました。 | Rokku ga kakatte shimaimashita. | It's locked. |
| 暗証番号の再設定をお願いします。 | Anshō bangō no saisettei o onegai shimasu. | I'd like to reset my PIN. |
Common mistakes with My Number
- Saying you have no My Number because you never applied. The number and the card share a name; the number arrived with the notice. Look for that envelope.
- Letting a gym or a rental shop copy both sides. Residence-card habits make people offer both sides. Offer the front only; the back is for employers and government.
- Typing the long password at the convenience store or the clinic. There are two certificates. Everyday checks use the four-digit PIN; the long one is for signing.
- Letting the card lapse after a status renewal. People assume immigration updates it. Ask the city office for a change of validity period before the old date.
- Guessing a forgotten PIN until it locks. Three wrong tries lock a four-digit PIN. After two misses, stop and go to the city office.