You may have already received your My Number, or Individual Number (Kojin Bangou in Japanese), or have been requested to provide it by the employer, or have heard about My Number Card frequently on the news that the application for 100,000 yen COVID-19 handouts can be submitted online if you own the My Number Card.
As a 12-digit number designated and notified to every resident in Japan, My Number is unique for everyone and keeps the same along our whole life, except for cases of leak or illegal use by others in which a new number can be issued at request. We are going to introduce more about My Number, when My Number may be requested (including requested by the employer), and the cases for part-time jobs where My Number should be provided to the employer.
My Number's whole system, whose official name is the Social Security and Tax Number System, is a social infrastructure aimed at improving administrative efficiency, enhancing public convenience, and realizing a fairer and more just society started from January 2016. Though the number is expected to be widely used in both public and private sectors, currently it can only be used in administrative procedures related to social security (pensions, labor, healthcare, welfare), taxation, and disaster response stipulated by the My Number Act.
Different from the resident registration number of South Korea that the first 6 digits represent the date of birth, My Number of Japan has no relationship with personal attributes so that it can't be analyzed from one's date of birth or address.
Everyone registered as a resident in Japan will be notified My Number, including foreign nationalities who own a medium to long-term residence status or special permanent residents. Foreigners holding a residence status for three months or less, a short term stay or diplomatic or government-related purposes won't receive My Number.
Once you file for the resident registration to a local municipality, My Number will be provided without special procedures and a Notification Card, a paper card, will be notified with My Number, full name, address, date of birth and gender printed.
Though the Notification Card has a permanent validity, it is just a paper and can't be used as an identification document alone. Another identification card with a face photo printed like driver license should be provided together to confirm identity. While My Number Card is much more convenient which is a plastic card containing an ID photograph and an IC chip. Both My Number and identification can be verified only with this My Number Card.
My Number Card can be issued upon request at local municipality office after receiving the Notification Card at will. There is no term of validity or due date for application, but the My Number Card is valid for 10 years if you are 20 years or older, and for 5 years if you are under 20.
For foreigners, My Number Card's expiration date also vary depending on residency period. If you have extended your period of stay, you may need to bring the card to local municipal office for an update within 14 days. So do other changes to the information printed on the card such as name, address, etc.
After My Number Card obtained, you can access the Mynaportal with a password set, which is an online web service provided by the government for us to confirm when and where our personal information was exchanged and confirm the personal information that the government agencies hold concerning our My Number as well as messages from government agencies. The Mynaportal "One-stop Service for Childcare" may be very helpful for those raising children in Japan related to application and other procedures of pregnancy, delivery and childcare.
Currently only administrative procedures related to social security, taxation, and disaster response may request My Number. Specifically, when you carry out employment, medical insurance and pension procedures, apply for welfare benefits such as public assistance, children's allowance, conduct tax procedures such as tax returns, you need to provide My Number to national government offices or municipal offices. If your employers or financial institutions need to conduct tax or social security procedures on your behalf, you will also need to present My Number to them.
When you send or receive money to or from your home country, you will have to present My Number to the bank or post office.
As said before, if your employers process tax or social health insurances on your behalf, they will require your My Number. If you are a regular employee, as tax and social insurances are all handled by the company, My Number is necessary. In the case of part-time worker, employers still need to handle tax and social insurance procedures for you which means that My Number will be required if the following cases occur.
My Number will be needed for year-end adjustment, etc. If you are a dependent, even if your annual income is less than 1.03 million yen, still My Number may be required by your supporter's employer for tax deduction.
Part-time workers must join social insurances if working hours and working days meet certain conditions, in which case My Number will be required by the employer.
You have the right to refuse providing My Number to the employer, and no penalty or discrimination is allowed by the law. All your employer can do is to request continuously. But considering that your tax and social insurances can't be processed successfully without My Number, it is recommended to cooperate with the employer.
Don't worry about My Number's leak or illegal use by employers, because the use of My Number by them and administrative agencies is restricted by law. Other entities are prohibited to collect or store My Numbers.