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Digital Europe Programme Once-Only Principle (OOP) Reduce administrative burdens on citizens and businesses.

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What is the Once-Only Principle?

Today, citizens and businesses often have to provide the same information multiple times when interacting with public administrations. But, from 2023, the Once-Only Principle will allow public administrations in Europe to reuse, or share, data and documents that people have already supplied, in a transparent and secure way.

Less administrative burden

Thanks to OOP, 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 manually upload the same data again and again.

Increased efficiency

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.

Protecting personal information

Websites will ask the user’s approval before using Once-Only Principle. Also, they will only request the evidences that they need for each specific procedure and are always required to obey data protection and privacy rules.

Communication across borders

The Once-Only Principle will enable public administrations in a Member State to use information that citizens or businesses provided in another Member State, thus facilitating online procedures across borders.

Part of the Single Digital Gateway

OOP contributes to the Single Digital Gateway Regulation which promotes online access to everything citizens and businesses need in order to get active in EU Countries.


Introducting OOP (2 MIN.)

Watch a short video on what the Once-Only Principle will be able to help you with. Let's get started.

Who can benefit from the Once-Only Principle?


We will help reduce administrative burden on citizens that execute procedures across the EU.


The Once-Only Principle will facilitate starting, running and closing a business across the EU.

Public Administrations

Public administration procedures throughout the EU will become more efficient and reliable.

Get involved

Currently DIGIT together with DG GROW and DG CNECT is running a preparatory action on the OOP. Join experts representing other Member States and participate in this action.

Participate(opens in a new tab)

Large scale pilots already working on Once-Only Principle

Digital Europe for All (DE4A)(opens in a new tab) TOOP.EU(opens in a new tab)


Learn more about OOP

Once-Only Principle Flyer (PDF, 729Ko)

Discover Monheim am Rhein Success Story

Use case poster (PDF, 1.09Mo)

Contact us and start your digital transformation

If you have any question regarding Once-Only Principle, feel free to contact us or join our user community for further discussion and support.

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