FAQ: About My Number System

• Q & A will be added as needed.
• At the end of each answer, it is written as (answer in X, 20 xx). There is one before August 2021, but this was answered on the Digital Agency website before Cabinet Office was established.

Q1-1 What is My Number (Individual Number)?

A1-1

My Number is a single 12-digit number for each person who has a resident record. It can be used for administrative procedures stipulated by laws and regulations or ordinance, such as social security system, tax system, and disaster response. By introducing a cross-sectoral number, it will be possible to reliably and quickly identify and confirm the personal information of the same person through the exchange of information between institutions, thereby improving the convenience of citizens, improving the efficiency of administration, and realizing a fair and just society.
(Updated June 2023)

Q1-2 What has changed before and after the introduction of My Number System?

A1-2

For example, information may be exchanged between national administrative agencies and local governments in order to confirm whether a person is eligible for a social welfare service or a reduction or exemption of social insurance premiums. However, before the introduction of My Number System, personal information is managed within each agency using different numbers, such as resident register codes, basic pension numbers, and health insurance numbers, so time and effort were spent on identifying individuals by name, address, etc. when exchanging information between agencies.

By introducing a common, cross-sectoral ID number for administrative procedures stipulated by laws and regulations or ordinance, such as social security system, tax system, and disaster response, it has become possible to identify individuals reliably and quickly. This will improve convenience for citizens, improve administrative efficiency, and realize a fair and just society.
(Updated March 2026)

Q1-3 What are the specific benefits of introducing My Number System?

A1-3

There are mainly 3 advantages of My Number.
The first is to make administration more efficient so that people and financial resources can be directed to the service of the people.

The second is to improve the convenience of citizens by reducing the number of attached documents in administrative procedures related to social security, tax, etc. and by providing a notification service through Mynaportal.

The third is to design a detailed social security system and realize a fair and just society by grasping income more accurately than in the past.
In addition, My Number Card and Mynaportal can be used without the My Number system itself, and will be used to the fullest extent as an important foundation of the digital society, including in the private sector.
(Updated December 2022)

Q1-4 In what situations is the My Number used?

A1-4

Laws and regulations and ordinance have decided who can use their My Number and in what situations. To be specific, national administrative agencies and local governments will use it for administrative procedures stipulated by laws and regulations or ordinance, such as social security system, tax system, and disaster response. Citizens are required to enter their My Number on application forms for pension, employment insurance, and medical insurance procedures, public assistance, child allowance and other welfare benefits, and tax procedures such as final tax returns.

In addition, tax and social insurance procedures may be performed on behalf of the individual by the employer or financial institution at the place of employment, and the My Number may be presented to the financial institution with which the individual has certain transactions, in addition to the employer.
(Updated March 2026)

Q1-5 In My Number System, will even deposits and savings and assets be seen by administrative officials?

A1-5

In order for administrative agencies to check the balance of personal accounts, it is limited to cases where necessary investigations (such as social security fund investigations and tax investigations) are conducted based on laws and regulations. Therefore, the introduction of My Number System does not mean that administrative officials will be able to see deposits and savings and assets anew.
(Updated June 2023)

Q1-6 Is it true that the company will find out about your side business in My Number System?

A1-6

My Number System does not change the procedures related to local taxes, and it does not newly reveal the fact that My Number System is conducting a secondary business.

Even before the introduction of My Number System, the amount of inhabitant tax, etc. was notified to the taxpayer via the salary payer by a notice of determination of the amount of special collection, and since the total amount of salary revenue for the previous year is stated in this notice, we believe that there was a possibility that the fact of engaging in a second job would be revealed by comparing the amount of salary paid by the employer.
(Updated June 2023)

Q1-7 Can I provide my My Number to anyone?

A1-7

As a general rule, it is restricted to provide My Number to administrative agencies, etc. for procedures stipulated by laws and regulations or ordinance, such as social security system, tax system, and disaster response. Tax offices, local governments, Hello Work (public employment security offices), pension offices, health insurance associations, employers, financial institutions, and others can provide My Number for these procedures.

Even if your My Number is seen by another person or leaked, you cannot complete the procedure with your My Number alone, so you cannot retrieve the information or abuse it immediately. However, please refrain from disclosing your My Number on your personal blog, SNS, etc., as it may be a "provision" of your My Number to a third party and may be a violation of the law.
(Updated June 2023)

Q1-8 Does the use of My Number eliminate the need for all attachments such as copies of resident records and taxation certificates?

A1-8

In November 2017, local governments and other organizations began full-scale operation of information linkage, making it possible to omit documents such as copies of residence certificates that had to be submitted in the past in administrative procedures stipulated by laws and regulations or ordinance, including social security system, tax system, and disaster response.
(Updated June 2023)

Q1-9 What are the "Person in Charge of Affairs Using the Individual Number" and "Person in Charge of Affairs Related to the Individual Number" stipulated in the My Number Act?

A1-9

A "Person in Charge of Administrative Affairs Using the Individual Numbers" is a national administrative agency, local public entity, or independent administrative agency that uses the My Number to handle administrative affairs specified in the My Number Act Annex or by ordinance. In addition, a "Person in Charge of Administrative Affairs Related to the Individual Numbers" is a person who submits a document stating the My Number to the Person in Charge of Administrative Affairs Using the Individual Numbers based on laws and regulations or ordinance.

For example, in tax matters, the Commissioner of National Tax Agency (Tax Office), prefectural governors, or mayor of municipality (in charge of tax) will be the Person in Charge of Affairs Using the Individual Numbers, and private sector, etc., who submits withholding records and payment records, etc., in which the My Number is entered, to these organizations, will be the Person in Charge of Affairs Using the Individual Numbers.
(Answer in March 2026)

Q1-10 Will the scope of use of My Number be expanded in the future without going through the laws and regulations Amendment?

A1-10

The the Act to Partially Amend the My Number Act (promulgated in June 2023) has decided to promote the use of My Number for administrative affairs outside social security system, tax system, and disaster response. However, in order to newly use My Number for "affairs based on the provisions of individual laws," it is necessary to continue to add administrative affairs through legal revisions.

In addition, the revision made it possible to use My Number for "equivalent office work" to those for which the use of My Number is permitted by law. The purpose of the revision is to improve the convenience of citizens and the efficiency of administration by eliminating the situation where the use of My Number is not permitted for such "equivalent office work," for example, because it includes "office work not based on an individual law," which is the same office work from the perspective of residents.
Standards such as the fact that the nature of administrative work is the same as administrative work for which the use of My Number is permitted by law and that it is limited to "administrative work not based on an individual law" are both stipulated by law and cannot be expanded beyond these at the discretion of the national government.

In addition, the content of "equivalent administrative work" will be stipulated by the ordinance of the competent ministry. Public comment is required for its revision.

If information about you is shared using the Information Providing Network System, you can check the records and the shared information at Mynaportal.
(Answer in March 2026)

Q1-11 What kind of corporation is Japan Agency for Local Authority Information Systems?

A1-11

Japan Agency for Local Authority Information Systems (J-LIS: Japan Agency for Local Authority Information Systems) was established on April 1, 2014 as an organization jointly operated by local governments. J-LIS carries out administrative work related to My Number, Basic Residential Registers Network System, etc., as well as administrative work related to local governments' information systems.

In relation to the My Number system, in addition to playing the core roles of generating numbers that will be the basis of the My Number system and notifying municipalities, the system is entrusted by municipalities to send notifications of individual numbers and create My Number Card.
(Updated May 2020)