ISA² - Interoperability solutions for public administrations, businesses and citizens

Open e-Prior

An e-Procurement system for Public Administrations

When is this solution for you? 

You are a European administration intending to switch to eInvoicing or eProcurement, or a system integrator working on an eProcurement approach for a European administration.

What can we offer you? 

Open e-PRIOR is a free open source e-Procurement platform that allows public administrations to implement interoperable electronic services. It plays the role of intermediary between the back-office applications of the public administration and the Pan-European Public Procurement OnLine (PEPPOL) interoperability initiative.

The platform has been designed to interoperate with a large number of applications of heterogeneous nature. It is connected to PEPPOL via its own Access Point, facilitating the cross-border exchange of e-procurement documents between, for example, a public administration in country A with suppliers in country B.

Open e-PRIOR currently covers:

  • e-Invoicing, i.e. reception of e-Invoicing business documents;
  • e-Submission, i.e. submission and opening of tenders;
  • post-award e-Procurement, i. e. documents exchanged between the public administration and its contractors after the award of a contract.

The Open e-PRIOR package includes also a web portal allowing suppliers, such as SME and individuals, to manually encode their invoices via a web form.

The latest version of Open e-PRIOR 2.1.0 was released in June 2017.

Our solution at a glance 

Read the e-PRIOR brochure.

Watch the e-PRIOR animation.

Get started 
  1. Download Open e-PRIOR software
  2. Access the e-PRIOR Supplier Portal: 

If you already have an EU Login account, you can access the Supplier Portal via your EU Login.

Is this solution open source? 
Any questions? 

Contact the Open e-PRIOR support team.

Contact the e-Procurement support team.

Contact the Interoperability Unit of DG Informatics (please use the subject line ‘Open e-Prior’).

More detailed information 
Who is already using this solution? 


Arnaud Reper

Belgian public administration:"e-Prior has allowed the Belgian federal and regional institutions to jump start the digital agenda regarding e-Invoicing. FOD BOSA/DT built the solution based on the Open e-Prior. It allowed the Belgian public sector to quickly start a pilot to gain knowledge in the definition of a proper e-Invoicing solution. e-Prior semantic and technical solutions allowed us to propose a mature and production-ready product to our partners. They are very pleased by the maturity of that solution.
Leveraging on the experience gained during the e-Prior pilot, FOD BOSA/DT launched the Mercurius platform combining a Peppol Access point with an e-Prior interface. The e-Prior interface allows the public institutions to receive and retrieve documents from our Mercurius platform, while the Peppol interface allows dynamic and fast interoperability with our suppliers based on the Peppol specifications. Currently the Mercurius platform has 125 receiving institutions and almost 5500 sending partners."

Arnaud Reper, Domain Architect at FOD BOSA/DT (Digital Transformation)

The tool is also used by more than 70 services of the European Commission and other European institutions.

Key facts and figures 
  • Number of suppliers connected via the web supplier portal: 306
  • Number of suppliers connected to the European Commission via web services: 36
  • Number of downloads of the open source version of e-PRIOR on 1 893