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Once Only Technical System (OOTS)Reduce administrative burden on citizens and businesses.

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What is the Once-Only Technical System?

The Once Only Technical System (OOTS) enables the sharing of information between public administrations across borders between EU countries. It is cross-sectorial and can be expanded beyond the current scope of life events set out in the Single Digital Gateway Regulation. It puts into practice the Once-Only Principle, which states that citizens should not be forced to provide information to authorities if another authority already holds that information in electronic format.

Less administrative burden

Thanks to the OOTS, when you execute a public procedure, the website can fetch and reuse any supporting evidence that you had already provided to another public administration. You no longer need to upload manually the same data repeatedly.

Increased efficiency

The OOTS will reuse EU-wide building blocks. For example, eDelivery will maintain high quality and performance levels, even if the number of participants in the network grows exponentially, as well as the number of exchanged messages. In addition, citizens will authenticate to any online procedure portal in Europe using their national eID.

Protecting personal information

The OOTS will greatly simplify online administrative procedures for EU citizens and businesses upon their explicit request. It is fully in line with personal data protection legislation as it puts users at the heart of the design of the way the system works.

Communication across borders

The Once-Only Technical System will make the first EU-wide data space a reality, connecting public authorities across the EU so that they can exchange official documents and data at the citizen’s request.

Part of the Single Digital Gateway

Operating within the Single Digital Gateway Regulation framework, the OOTS promotes the simplification of cross-border online procedures, making it easier for citizens to study, move, work, retire or do business across the EU.


Introducing the Once Only initiative (2 MIN.)

Watch a short video introducing the Once Only initiative. Let’s get started.

What will change for citizens and businesses in 2024?

As of 2024, thanks to the Once-Only Technical System, it will be easier for citizens to study, move, work, retire or do business across the EU. The OOTS will connect public authorities across the European Union, so they can exchange official documents and data at the citizen's request.


Authenticate to any online procedure portal in Europe using their national eID.


Benefit from the OOTS to help find the equivalent document in any Member State required for that procedure.

Public Administrations

Request that the document or data is shared between the authorities in order to complete that procedure.

“Countries voted YES on creating a #dataspace between administrations. Meaning? If administrations require a document for cross-border procedures… THEY must RETRIEVE it. And it's NOT the citizen who must upload it multiple times! By when? December 2023! #OnceOnly

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Kerstin Jorna Director General of Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs (GROW)


Learn more about The DIGITAL Europe Programme - Work Programmes - Shaping Europes's digital future

The DIGITAL Europe Programme - Shaping Europes's digital future (PDF, 2,69 MB)

Contact us and start your digital transformation

If you have any question regarding the Once Only Technical System, feel free to contact us.

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