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mathematics

My Number Card

My Number Card is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand My Number Card rather than just read about it. In short: The My Number Card (Japanese: マイナンバーカード, Hepburn: mai nanbā kādo), officially Individual Number Card (Japanese: 個人番号カード, Hepburn: kojin bangō kādo), is an identity document issued to citizens of Japan and foreign residents which contains a unique 12-digit Individual Number (Japanese: 個人番号, Hepburn: kojin bangō) that serves as a national identification number in Japan. Unlike similar-looking identity cards in Europe…

My Number Card — main illustration
My Number Card — illustration

Key takeaways

  • My Number Card belongs to mathematics; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect My Number Card to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of My Number Card from memory before moving on to harder problems.

Reference excerpt

The My Number Card (Japanese: マイナンバーカード, Hepburn: mai nanbā kādo), officially Individual Number Card (Japanese: 個人番号カード, Hepburn: kojin bangō kādo), is an identity document issued to citizens of Japan and foreign residents which contains a unique 12-digit Individual Number (Japanese: 個人番号, Hepburn: kojin bangō) that serves as a national identification number in Japan. Unlike similar-looking identity cards in Europe, the My Number Card can be issued to both Japanese citizens and foreign residents, and is not proof of nationality. The My Number Card is used in Japan to streamline administrative purposes like filing taxes and social security, and it is also utilized to provide disaster response to those in need. It is the de facto Japanese equivalent to a U.S. Social Security Number. The My Number Card stores information such as personal name, photo, address, birthday, and sex. Residents who wish to obtain the card can request an application form from the municipality (via a ward office or city hall) where they reside.

History

Background Many countries around the world, including Japan, require residents and citizens to disclose and register their address with the government for various bureaucratic purposes. Many countries obligate that their residents and citizens provide up to date information regarding where they reside, by visiting a registration office or the police within a few days after establishing a new residence. However some countries, like the United States or Canada, do not require their residents or citizens to provide this information to the government, unless they are applying for a passport or drivers license. Both Japanese citizens and foreign residents are obligated to report their domicile to their nearest municipal government office.

Basic Resident Registers Network In 2002, the Japanese government created the Basic Resident Registers Network and started to issue unique 11-digits identity codes at request to people who did not possess a drivers license, but wanted a identity card to prove legitimacy when applying for a Japanese passport, obtaining copies of their family registry, or any other activities that require ID. These identity codes provided information regarding the bearer's name, date of birth, gender, address, and the identity code itself. By 2003, the Japanese government started to issue a Resident registration card (住基カード, Jūki kādo), which are physical cards with IC chips linked to these identity numbers. Both the Basic Resident Registers Network and the Jūki kādo were negatively received and had widespread opposition from people, political parties, and prefectures. Despite this, in 2008, the Supreme Court of Japan ruled the Basic Resident Registers Network and subsequent affiliations constitutional.

Individual Number and My Number Card Beginning in 2015 the Japanese government started to make significant steps in overseeing Japan's transformation to a digital economy, and established a new government office titled the Minister for Digital Transformation. Under this new cabinet, the Japanese government started to phase out the Basic Resident Registers Network system's 11-digits identity codes, in order to establish a new modern system of unique 12-digits codes, called the Individual Number (Japanese: 個人番号, Hepburn: kojin bangō). These codes were issued to all Japanese citizens and foreign residents in a unsolicited manner. To advertise the system's introduction, the Government of Japan hired actress Aya Ueto and created a mascot character named "Maina-chan". Beginning in March 2021, the Japanese government began to issue My Number Cards embedded with IC chips that can double as health insurance cards. These cards can be read by card readers, and in conjunction with facial recognition, give facial medical care providers instant access to patients' past health checkup results and prescription drug history. They are accepted at all medical institutions, and separate health insurance cards will no longer be issued as of December 2024. The rate of uptake for the cards in Japan was around 25% in March 2021 and 40% as of October 2021. The government aimed to have almost all residents obtain the card by March 2023. In May 2023, an Android app became available allowing people to use their phone instead of their My Number Card. This later evolved into a plan to support My Number Cards in Google Wallet. The launch of this feature is planned for 2026. In June 2025, it became possible to add My Number cards to Apple Wallet on iOS. In June 2026, the Japanese government introduced the integration of "Tokutei Zairyū Card" (特定在留カード / Specified Residence Card) with the My Number Card for mid-to-long-term foreign residents registered on the Basic Resident Register. Under this voluntary framework, the Immigration Services Agency allows eligible residents to consolidate the administrative functions of the Residence Card and My Number Card into a single IC card.

Features The My Number Card, although not a required document, may simplify access to certain government services. Not only is it an accepted form of ID across Japan, it can be used to access National Health Insurance, apply for a Japanese passport, open a bank account, and obtain vaccination certificates. The Ministry of Internal Affairs and Communications promotes a cashless payment card called Mainapoint (マイナポイント) linked to a person's My Number.

Identification of national public officials

The My Number Card is used as an ID card for civil servants in the Japanese government. A masking card, in which the photo and name fields of the My Number Card are cut out so that they can be seen from the outside, is stacked on top of the My Number Card and stored in a Fujifilm card case to serve as identification for national public officials and civilian officials of the SDF. In addition to the name of the ministry or agency to which the person belongs, the masking card has a signature column to prevent identity theft.

Issues The first fraud related to the system occurred in 2015 when an elderly woman in the Kantō region was defrauded of several million yen. The program was temporarily paused in May 2023 due to 13 confirmed cases of another person's information being displayed when the card was used.

See also

Individual Number Basic Resident Registry Card

References

External links Official website

Illustrations

My Number Card illustration
My Number Card illustration
My Number Card illustration
My Number Card illustration
My Number Card: A masking card
A masking card

Worked examples

Example 1 — a first encounter with My Number Card

Start with the simplest possible case. Write down what My Number Card claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to My Number Card before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about My Number Card ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of My Number Card

In research
My Number Card appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses My Number Card in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
My Number Card is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2016 establishments in Japan, Government of Japan, National identity cards by country, so understanding it makes those chapters shorter.
In everyday life
Look for My Number Card outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study My Number Card in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what My Number Card means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain My Number Card out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is My Number Card in simple terms?

The My Number Card (Japanese: マイナンバーカード, Hepburn: mai nanbā kādo), officially Individual Number Card (Japanese: 個人番号カード, Hepburn: kojin bangō kādo), is an identity document issued to citizens of Japan and foreign residents which contains a unique 12-digit Individual Number (Japanese: 個人番号, Hepburn…

Why does My Number Card matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study My Number Card?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on My Number Card.

Tags

  • 2016 establishments in Japan
  • Government of Japan
  • National identity cards by country
  • Smart cards

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