The “One-Only” Principle Project

Past project


The European Union strives to further develop the common digital single market by lowering the administrative burden for citizens and businesses. In 2009, Ministers of EU Member States agreed upon a Ministerial Declaration that they plan to use e-Government to reduce administrative burdens, partly by redesigning administrative processes in order to make them more efficient.

One of the major impediments to a well-functioning single European market is the grinding daily friction of procedures and paperwork imposed by the public sector. Therefore “once-only” principle (OOP) is a viable way to reduce the administrative burden throughout the EU member states and make the digital single market a reality. It is based on the assumption that collecting information is more expensive and burdensome than sharing already collected information. Hence this principle proposes to collect information only once and then share this information, respecting other constraints, such as regulations. 


The project aims to explore and demonstrate the “once-only” principle through three sustainable pilots: Cross-border e-Services for Business Mobility, Updating Connected Company Data and Online Ship and Crew Certificates. 

TOOP has the ambition to connect 59 information systems from 20 countries, using a federated architecture on a cross-border collaborative pan- European scale in order to identify drivers and barriers and to provide a basis for future implementations and wider use. The Luxembourg Institute of Science and Technology (LIST) will participate in the Online Ship and Crew certificates Pilot, collaborating with the Administration of Maritime Affairs (CAM) to implement the Maritime pilot.

TOOP’s main technological innovation is a generic federated OOP architecture that supports the interconnection and interoperability of national registries at the EU level. The pilots planned are ambitious as they contain product, service and organisational innovations not existing in the market today and provide a basis for recommendations for future implementations and the wider use of OOP.


TOOP is expected to bring numerous benefits, among them time savings and cost reductions for businesses and administrations by reducing the administrative burden as demonstrated by the pilots carried out and generates valuable insights in how to extend OOP, what the drivers and barriers are and which obstacles need to be overcome. 

The project is thus an important learning environment for OOP in particular and European e-Government in general. The pilots are scalable and can be extended to all Member States in subsequent years. 

TOOP will also lay good foundation for this via its contribution to European frameworks, standards and guidelines that derive from pilots and from integration with OOP federated architecture and for addressing building blocks sustainability considerations. The project contributes to the key e-Government, public administration development and economic development strategies of the EU. 

The project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 737460.

Research domains
  • IT

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 Pascal LHOAS
Pascal LHOAS
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