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Once Only

Digital technology makes administrations more efficient and creates greater trust between administrations and users. Public authorities can authenticate and check information thanks to authentic sources, which are specific databases. This means that citizens and businesses no longer have to become involved unnecessarily in administrative processes.

Click here to inform us of a procedure that doesn’t comply with the “Once Only” principle

An essential key to administrative simplification

The advantage of authentic sources for administrations lies in the fact that they are safe and practical. They allow administrations to make life easier for users, become more flexible and operate better and more autonomously, without disturbing users. This means that they reduce the administrative burdens on citizens and businesses, avoiding unnecessary expense and travel that can impact their schedule.


Two major principles for users

Authentic sources thus first and foremost meet the needs of users.

As a result, citizens and businesses

  • no longer have to systematically enter information when a file is submitted. The authorities apply the principle of trust. They rely on the user’s declaration. This saves a lot of time the users. The administration can always check the data later if it needs to.
  • no longer have to provide information they have already shared with an administration. Users only have to provide information once and it is then collected and shared within the administrations. This is the Only Once principle of data collection.

Privacy protection

The subject of authentic sources leads to questions about respect for privacy, which is why their use involves strict safety and confidentiality conditions.

To be recognised as an authentic source and guarantee effective information management, a database must:

  • be validated by one or more administrations
  • be regularly updated by one or more administrations
  • be legitimated by at least one administration that acts as the unique authentic source manager


Access to the database is secure and monitored.

The most frequently used authentic sources at federal level are:

  • the national Register, which includes personal information about Belgian and foreign citizens living in Belgium.
  • the Crossroads Bank for Enterprises (CBE), which centralises the key data on legal persons, businesses and units of establishment.

Authentic sources in Brussels

In the Brussels-Capital Region, the Fidus platform, managed by the BRIC (The Brussels Regional Informatics Centre) is the legal manager of data exchanges from authentic sources. These exchanges can be between Brussels and federal institutions, as well as at intra-regional level.

Easybrussels is encouraging Brussels institutions to use authentic sources at both regional and local levels thanks to the advantages they offer for administrative simplification. To do so, the agency is working closely with the BRIC to raise awareness among the administrations.

You wish to inform us of a procedure that could be simplified?

In the context of its missions, Easybrussels makes sure that the Once Only principle is implemented in the Brussels-Capital Region. According to this principle, administrations can no longer ask you for information that can already access (for example: household composition, fiscal documents, social certificate, etc.).

You can inform us of any administrative procedure related to a public administration of Brussels (regional, local, public association, etc.) that doesn’t comply with the Once Only principle or that could be simplified. To do so, please fill in the following form:


Once Only signalement EN
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