The My Number Card: Japan's Most Important Little Piece of Plastic (2026 Guide)

My Number (マイナンバー) and the My Number Card explained for foreign residents: what it is, how to get it, and why it now doubles as your health insurance card.

Updated October 2026: the short grace period for expired paper insurance cards ended on 31 July 2026, so it's now マイナ保険証 (maina hokensho) or a certificate of eligibility only. And since 14 June 2026 you can choose a residence card that doubles as your My Number Card (特定在留カード, tokutei zairyu card); see the foreign residents section.

What "My Number" actually is (and why everyone keeps asking for it)

My Number (マイナンバー), officially the Individual Number, is a unique 12-digit number given to every resident of Japan — including foreign residents, the moment you finish your move-in registration at city hall. You get exactly one, and it stays with you for life.

Two things often get mixed up:

  • The number itself — 12 digits, used for tax, social insurance and your bank. It arrives by mail (the 個人番号通知書, kojin bango tsuchisho, "Individual Number Notification") a couple of weeks after you register your address.
  • The My Number Card (マイナンバーカード) — an optional plastic IC card with your photo. This is the one worth getting, because it has quietly become the key to most admin in Japan, both online and at the counter.

Why the Card is worth getting

  • Official photo ID — a single card that proves both who you are and your My Number.
  • Health insurance (マイナ保険証) — this is the big one. Japan stopped issuing the old health insurance card on 2 December 2024, and the last of the old cards expired on 1 December 2025. Clinics kept accepting expired cards for a while, but that ended on 31 July 2026. Once registered, your My Number Card is your health insurance card now (some clinics even take it on your smartphone), and the hospital sees your monthly cost cap automatically. Do not have one yet? Your insurer automatically sends a "Certificate of Eligibility" (資格確認書, shikaku kakuninsho), free, so you can still see a doctor with no card.
  • Taxes — file your year-end return (確定申告, kakutei shinkoku) online with e-Tax by scanning the card with your phone, no trip to the tax office.
  • Mynaportal (マイナポータル) — a government portal where you check your pension, tax, insurance and child-related records, and register a bank account for public payments (公金受取口座).
  • Convenience-store certificates (コンビニ交付) — print your residence certificate (住民票, juminhyo) and seal registration at a konbini multi-copier, often cheaper and later in the day than the city office.

How to get the Card (it is free)

You apply once, then pick it up in person:

  1. Apply with the application ID on your notification — by smartphone, PC, post, or a konbini photo booth. You need a passport-style photo (the smartphone app takes it for you).
  2. Wait about a month while it is produced, plus a few more weeks until your city sends the pickup notice.
  3. Pick it up at your city or ward office once they mail you the collection notice. Bring that notice, your residence card, and your notification, and set your PINs (a 4-digit PIN plus a longer signature password).

Tip: do it early. You will want it for health insurance and your tax filing, and pickup slots can book out.

What is different for foreign residents

  • Validity follows your visa. For most foreign residents the card's validity matches your period of stay. When you renew your residence status, update the card's expiry at city hall on the same trip.
  • Moving? Bring the card to your move-out and move-in (転出・転入) so your new ward can update the address on the chip.
  • Lost it? Call the 24-hour hotline to suspend the chip, then report to city hall and your local police to get it reissued.
  • Two cards in one (特定在留カード). Since 14 June 2026, mid- to long-term residents registered at a city hall can get a residence card that also works as their My Number Card. It's optional, so you can keep two cards. You ask for it at immigration when you renew or change your status (or simply ask to swap cards), or at city hall when you register your address after arriving or moving to a new town. The perk: immigration updates the My Number side at the same time, so no extra city hall trip. The catches: you can't request it through the online residence application, it takes about 10 days longer than a normal residence card, and its My Number functions still stop at the end of your current period of stay. If your renewal is still pending then, update the card's validity at city hall so your マイナ保険証 keeps working.

Bottom line: the number is automatic, but the Card is what saves you trips and unlocks online admin — especially now that it doubles as your health insurance card. If you do one "nice to have" admin task this month, make it this one.

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