Search services of the Population Information System

The search services of the Population Information System (VTJ) are intended for situations where your organisation needs personal data, building information or information on dwellings available in the VTJ

  • on a continuous basis (the activities and the need for the information are not on a one-off basis)
  • individually (not in large batches and not for such purposes as updating your customer register)
  • in updated form (as retrieved from the Population Information System, with no delays).

There are two search services in the Population Information System:

  • VTJkysely, a browser-based application, which can be used as such by your organisation’s employees and
  • VTJ query interface, which receives and returns XML messages and which can be integrated into your own information system.

In both services, the exact data content disclosed to the customer organisation is determined with the Digital and Population Data Services Agency on a case-by-case basis. As a rule, unique identifiers (such as the personal identity code or the building code) are used as search criteria.

Applying for the data access authorisation is always the first step in getting access to VTJ search services. Instructions for making the application are given below. The information stored in the VTJ is not publicly accessible.

VTJ query interface

With the VTJ query interface, you can make real-time searches from the Population Information System and process the retrieved data in your own information system. Using the VTJ information, you can provide your own customers with e-services or check the accuracy of the information when processing applications. Data in the query interface is retrieved and received as XML messages.

Introducing the query interface requires slightly more work than the browser-based VTJkysely application. The work involves information system development, protection of data processing and keeping of logs. However, with the application, you can process VTJ information more flexibly in a system tailored to your needs.

As a rule, you cannot make regular and/or comprehensive updates of your own registers with the VTJ query interface. The customer register update services of the Digital and Population Data Services Agency are well-suited for such information needs.

Public administration organisations can only open the connection using the Data Exchange Layer. Using the Data Exchange Layer is only mandatory for public administration organisations, but other organisations are free to do so as well.

If you want an alternative to a direct VTJ query interface, you can also contact companies granted the right to relay information retrieved through the VTJ query interface and ask them about services based on VTJ information.

Browser-based VTJkysely application

VTJkysely is a browser-based service provided by the Digital and Population Data Services Agency where you can retrieve real-time personal data, building information or information on dwellings from the Population Information System. VTJkysely is the right choice for you if your employees must, as part of the duties, access the Population Information System to check up-to-date personal data, building information or information on dwellings and you do not have any need or chance to retrieve data from the Population Information System for your own information system.

Organisations granted access to the VTJkysely service must have at least one person (system administrator) coordinating the use of the service in the organisation. The obligations of the system administrator include: monitoring the way in which other employees granted access rights use VTJ information, apply for access rights for new users and ensure that the access rights of former users are terminated. The system administrator must also notify the Digital and Population Data Services Agency of the changes in the details of the organisation (contact information, contact persons, name of the organisation, etc.).

For more information

If you would like more information on these matters, please contact

  • VTJ interface experts at vtj-rajapinta(at)

  • VTJkysely experts at vtjkysely(at)

Related links

VTJ query interface


Please note! The personal identity code will be reformed starting at the beginning of 2023. No changes will be made to the current personal identity codes. Additional information on the reform can be found on the page Reform of personal identity codes.