Implementing the OOTSOnce-Only Technical System Acceleratormeter

The Once-Only Technical System Acceleratormeter tracks the Member States’ progress towards setting up their national OOTS infrastructures at the technical level.

What is the OOTS Acceleratormeter?

The Member States are currently implementing the Once-Only Technical System. It will allow citizens and businesses to request the exchange of official documents, or "evidence," needed for administrative procedures between the competent authorities involved. This will make it easier for people to study, work, live, or retire when moving between EU countries.

The adoption of Once-Only means the creation of "search-free" administrative procedures, where data comes to individuals and businesses automatically without the need to search for it online. Thereby, Once-Only lays the foundation for shifting from document-centric to data-centric processes.

To support the Member States in this development process, the Commission regularly organises large-scale testing events, known as OOTS Projectathons and Accelerators. During these events, the Member States perform integration activities, readiness checks and interoperability tests to ensure that they can correctly exchange information through the Once-Only Technical System, while receiving custom support and advice from Commission experts. These events are great opportunities for the Member States to test their systems with one another to advance their Once-Only Technical System implementations.

The Commission has introduced the OOTS Acceleratormeter to create a comprehensive mapping of where the Member States stand in their development. The OOTS Acceleratormeter is a useful tool to track Member States’ progress in implementing the Once-Only Technical System as they accelerate their implementation through OOTS testing events. During these events, the Member States perform tests, which also show whether they are ready to move to the next level in the OOTS Acceleratormeter.

While the Member States move along the six levels of the Acceleratormeter, details on which can be found below, they become increasingly technically ready for setting up their national OOTS infrastructures at the technical level and providing Once-Only services to EU citizens and businesses.

Please note that:

The OOTS Acceleratormeter provides a snapshot of the current level of OOTS implementation in a Member State and is regularly updated by the Commission to reflect the Member States’ current implementation status. The Member States are working continuously to advance their national OOTS implementations. Therefore, their position on the OOTS Acceleratormeter will likely change over time.
It is important to keep in mind that the OOTS Acceleratormeter tracks technical readiness in terms of rolling out the OOTS services. The Member States are carrying out other activities to advance their national OOTS implementations, e.g., evidence mapping or outreach activities to the national Competent Authorities. Thus, although the OOTS Acceleratormeter is a useful tool for monitoring the Member States’ progress, it does not depict the full range of Member States’ activities related to the implementation of the Once-Only Technical System. You can find video testimonials of how the Member States are implementing Once-Only further below.

The OOTS Acceleratormeter

The OOTS Acceleratormeter consists of six levels. Each Member State is represented by its flag, showing the Member States’ current position in the OOTS Acceleratormeter. The Member States move through these six levels from left to right. Moving to the next level means that the Member States have progressed further in setting up their national OOTS infrastructures at the technical level and providing Once-Only services to EU businesses and citizens.

Reaching level six of the OOTS Acceleratormeter means that the Member States are technically ready to exchange evidence through the Once-Only Technical System. However, the development of the Member States’ OOTS implementations is far from over. Empowered by a strong, tested infrastructure, the Member States now roll out their Once-Only services and make them gradually available to more citizens and businesses. The Member States consider end-users’ feedback and continuously improve the system.

The six levels of the OOTS Acceleratometer

Initial

The Member States are preparing their national development and integration with the Once-Only Common Services. Each Member State is tackling unique challenges when starting to implement the OOTS.

Preliminary

The Member States have started developing their national OOTS infrastructures and connecting to the Once-Only Common Services. Several components are still incomplete or not fully automated.

Intermediate

Development of the national OOTS infrastructure and integration with the Once-Only Common Services are progressing. Most of the components are ready or on track to be ready in the coming months, but some technical items are still blocking technical readiness.

Technically ready

The national OOTS implementation is technically ready, and Member States are finalising their configurations. Now, Member States need to connect evidence providers and evidence requesters to make their first transactions through the system.

First live transactions

At least one evidence provider or evidence requester is connected to the system. The Member State has successfully tested exchanging evidence with another Member State, so their service is tested and configured.

End-user transactions

At least one or multiple evidence providers or evidence requesters are connected to the system. The services are ready to be rolled out and used by citizens and/or businesses.

How is the OOTS being implemented?

The European Commission and the Member States are jointly implementing the Once-Only Technical System.

Development of a national infrastructure

The Member States are implementing the OOTS at national level. Each Member State develops the technical infrastructure needed to exchange documents and data – known as ‘evidence’ – through the OOTS.

Integration with the Once-Only Common Services

The Member States’ national implementations are connected to the Once-Only Common Services. Provided by the Commission, these OOTS components help the Member States facilitate the exchange of evidence through the OOTS. The Common Services are live and ready for use since December 2023.

Onboarding of Competent Authorities

The Member States connect national Competent Authorities (known as evidence requesters and evidence providers) to their national OOTS infrastructures to enable them exchanging evidence through the OOTS. The Commission is organising testing events to support the Member States in connecting with Competent Authorities across Europe, such as Projectathons and other events, e.g., Europe goes Once-Only – Finland edition.

Testing and readiness checks

Supported by the Commission, the Member States and national Competent Authorities perform integration activities, readiness checks and interoperability tests to ensure that evidence can be correctly requested and provided through the Once-Only Technical System. This is done in the context of large-scale testing events, known as OOTS Projectathons and Accelerators.

After the Member States have completed the aforementioned four activities, they are ready at the technical level to make the Once-Only services available to citizens and businesses.