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The Nordic and Baltic Countries Work Together to Find the Best Solutions for SDG OOTS Implementation

The SDG Once Only Proof of Concept Pilots project was conducted 2021-2023 and was based on the Nordic and Baltic countries' shared interest to clarify the costs and functionality of Once Only architecture in the EU Single Digital Gateway Regulation (SDGR).

SDG OOP Poc Pilots Project

The EU Single Digital Gateway (SDG) regulation aims at helping citizens and businesses in cross border situations. It calls for full digitalisation of 21 specified life events and creating a digital gateway ( which provides information, guidance and access to eServices. It also calls for creating a Once Only Technical System (OOTS) for providing evidence needed in the 21 life events from data services in EU/EEA member states.

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The project aimed at testing the high-level architecture for EU Single Digital Gateway Once Only Technical System (OOTS) and finding the best possible solutions on implementing it for the Nordic and Baltic countries.

The high level architecture for OOTS was tested with proof of concepts: first by testing the individual parts of the system and finally the process as a whole. The PoCs were:

  • eDelivery Access Point
  • Identity Matching
  • Common Components
  • Evidence Request Service
  • Test Versions of Registers
  • Preview Service

The project deliverables were also be taken to the Projectathon testing event arranged by European Commission in April to enable interoperability testing with other EU member states.

Other goals of the project were to clarify the evidences to be exchanged via the OOTS, the eServices related to the 21 life events mentioned in the Annex II of SDGR, and the data services containing the needed evidences in each participating country. In addition, the project wanted to clarify the needed changes in national legislation of participating countries and a legal assessment checklist was created as a tool to support that work.

The project countries are Denmark, Estonia, Finland, Latvia, Lithuania, Norway and Sweden. The project is managed by the Development and Administrative Services Centre (KEHA Centre) in Finland and is running from 2021-2023.

Cross Border Digital Services Programme

The project is a part of the Cross Border Digital Services (CBDS) Programme which is funded by the Nordic Council of Ministers (NCM). The vision of NCM is that the Nordic-Baltic region will be the world's most intergrated region in the world.

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The components developed in the project as proof of concepts are released open source so that all project countries and other EU member states can utilise them.

The available components are Evidence Request Service Component created by KEHA Centre in Finland and the Preview Service Component created by Swedish Agency for Digital Government, DIGG.

Some of the project countries opted to build their eDelivery Gateway themselves based on Domibus. Some countries took into use the Harmony eDelivery Gateway component created by Nordic Institute of Interoperability Solutions which is developed based on Domibus and is a more ready-made solution.

The project has delivered a report on the situation of Identity Matching in Spring 2023 in the participating countries. In addition, reports on the phases of the project are available by request.

The project also delivered a check list for checking the possibly needed changes to national legislation.

Contact information for the project and its deliverables

Mervi Kylmänen-Paakki, Project Manager, Development and Administrative Services Centre (KEHA Centre)