EESSI (Electronic Exchange of Social Security Information)

Attention: from 1 January 2022: only on behalf of the Walloon Region, the Common Community Commission and the German-speaking Community!

As part of the standardization and modernization of information exchange between European countries, the European Commission has set up an electronic information exchange system for all branches of social security: EESSI (Electronic Exchange of Social Security Information).

Since May 1, 2010, the legal basis for this project has been laid down in the following consolidated European regulations:

All social security institutions in all Member States have to adapt for the implementation of the project at their own level.

The Belgian part of the project is called BelEESSI.

The initial deadline for the implementation of this network was 1 May 2012, i.e. 2 years after the entry into force of the new European regulations. In the end, it appeared that this would not be feasible. The 1st version of the project was abandoned and a new project was launched. It is currently well on its way to completion.

EESSI is a messaging system that replaces the exchange of “paper” forms between institutions with the exchange of electronic forms: SEDs (Structured Electronic Document). For the family benefits sector, there are 15 SEDs which fit into 4 different scenarios called BUCs (Business Use Case).

The SED’s and BUC’s have been read, modified and approved by the various Member States. After a transition phase, the first electronic exchanges of the EESSI system were tested by the countries that had volunteered.

In June 2017, the European Commission declared that the EESSI system was fit for purpose in accordance with the decision of the Administrative Commission. Member States therefore had a period of 2 years for the actual implementation of EESSI at national level. The date for putting EESSI into production was set at 2 July 2019. However, given the amount of work generated by the new system, not all social security sectors in all Member States managed to be ready on time. For this reason, the transition period has been extended. However, exchanges are taking place and the majority of Member States are gradually entering the system.

As far as our country is concerned, the information sent by a Member State and which transits through the European level, will go through a single entry point (Access Point): the BCSS (Crossroads Bank for Social Security).

In order to connect to the Access Point, Belgian institutions can choose between three possibilities:

  • By RINA (Reference Implementation for National Application), a program provided by the European Commission that works like a mailbox. It is a software with several modules. It is possible to receive requests, consult them and send answers. A request that is insufficiently referenced can be directly refused. However, this program will not allow the documents to be filled in automatically.
  • A national application (by sector) developed internally by the institution with a contact to the Access Point. A major advantage of this application is that it will be directly adapted to the needs of national institutions in their own area, through further and more automated developments. For this option, a facilitating interface, the National Gateway, is foreseen for exchanges between the Access Point and the national application.
  • A mixed solution, between some RINA modules and a own application.

It is important to note that in addition to the developments that have been made for the BUCs and SEDs in its sector, the institutions have also analysed the horizontal BUCs and SEDs, i.e. those used by all sectors among themselves.

Alongside all these European developments and to accompany them as the project progressed, workshops (Reflection Forum) were set up, bringing together representatives of the Member States. The goal of these workshops was to explore the options, parameters and constraints affecting the implementation of the EESSI system in order to establish, in the long term, an overall strategy which, if properly managed and executed, will make it possible to achieve the objective of implementing and operating EESSI in all the Member States within the time available.

At the Belgian level, the BelEESSI project bringing together people from the Federal Public Service Social Security (FPS Social Security) and the BCSS has been set up to help institutions to implement the EESSI project internally. Various meetings were held between the BelEESSI group and the Interregional Body (formerly the Federal Agency for Family Allowances) to establish the strategy to be adopted in the family allowance sector.

At the level of family benefits, Belgium went into production on 6 December 2021.

List of family benefits BUCs

  • FB BUC 01 – Determining competences
  • FB BUC 02 – Discharge of Family Benefits
  • FB BUC 03 – Additional Family Benefits for orphans
  • FB BUC 04 – Information about payment regarding priority right

List of family benefits SEDs


  • F001 – request for determining competence
  • F002 – reply to determining competence
  • F004 – request for clarifications
  • F005 – reply to clarifications
  • F022 – request for information of periods
  • F023 – reply to information of periods
  • F026 – request more information
  • F027 – reply to more information


  • F016 – request for discharge of benefits
  • F017 – reply for discharge of benefits


  • F018 – request for insurance length period of additional benefits
  • F019 – reply for insurance length period of additional benefits
  • F020 – information on priority for additional benefits
  • F021 – demandes de prestations supplémentaires – application for additional benefits


  • F003 – receipt of application for family benefits