32px_Search Created with Sketch.
Shape Created with Sketch. Back to projects

Electronic invoice

Since November 2020, all public contracts awarded by and with the regional public administrations of the Brussels-Capital Region must be invoiced electronically: invoices sent in another format (paper, email, etc.) will no longer be processed.
Since November 2022, this obligation will also be extended to local governments for public contracts over €3 000.

Electronic invoicing




What is an electronic invoice?


An invoice is an accounting document which requires a number of steps before it can be archived: creation of the invoice, printing, transmission, sending, reception, sorting, encoding, verification and approval, payment and, lastly, archiving.

The electronic invoice eliminates or automates some of these steps for both the supplier and the customers (administrations):


An electronic invoice is an invoice that has been submitted, transmitted and received in a structured electronic form that allows automatic and electronic processing.

  An invoice sent by email in other formats (pdf, xls, xml, etc.) is therefore not considered an electronic invoice.

Electronic format differs from the simple PDF format by the secure framework it guarantees: the dematerialised document is sent to the customer via a secure platform, in a structured electronic form that allows its automatic processing.


What are the benefits?


Electronic invoicing is part of the dematerialisation of the purchasing process. It is a tool for administrative simplification for both suppliers and administrations.

In addition to savings (reduction of printing, sending, payment time), electronic invoicing also ensures a gain in efficiency (elimination of possible encoding errors, guarantee that the invoice reaches the right department) and transparency (the supplier can monitor the invoice status).

On top of these benefits is the reduction of the environmental impact, which reinforces the importance that the public service must attach to this tool.


How does it actually work?


Automated invoice processing requires that both business and customer IT systems speak the same language. Europe has therefore created a framework, called PEPPOL, which facilitates the circulation of invoices in the European Union. It has also defined a standard format for structured invoices, the European Standard for Electronic Invoicing. These two elements combined enable the use of electronic invoicing on a large scale.

In practice, electronic invoices are sent by companies using the European Peppol network.

Different access points allow connection to this Peppol network.

Companies that send invoices can connect via their ERP systems, their accounting software or by using the Mercurius portal.

To receive electronic invoices, the Belgian public administrations use a specific platform called Mercurius.

To access the Mercurius platform, each Brussels administration uses the “Fidus” interface, developed by the BRIC (Brussels Regional Informatics Centre). Fidus’ objective is to act as an interface between Mercurius and the Brussels public administrations and therefore play a role in the security and reliability of Authentic Sources.


What are the legal requirements for electronic invoicing in the Brussels Region?


Invoices must be sent electronically to the Brussels regional authorities for all public contracts awarded from 1 November 2020

From November 2022 onwards, the obligation to use electronic invoicing will gradually be extended to all Belgian public institutions, including local governments (for all public contracts over €3,000).
However, if they wish, administrations can decide to impose electronic invoicing on their suppliers earlier, by indicating it as a condition in the specifications for their public contracts.

You are a company (supplier) 


How do you send electronic invoices?


According to the European standard, electronic invoices must be sent in XML format and sent directly to your customer via the Peppol network.

 Other formats (pdf, xls, etc.) sent by email are not considered electronic invoices according to this standard and can therefore be refused by the administrations.

Several scenarios are possible:

You have an ERP system

If you issue a lot of invoices, you probably already have an ERP (Enterprise Resource Planning) system. If your ERP does not yet allow invoices to be sent via PEPPOL, you must change your ERP via your access point.
You can find more information in our guide to electronic invoicing.

You use an accounting and invoicing software

If you already have standard accounting and invoicing software, ask your supplier or check on the internet if they plan to send electronic invoices via the Peppol network.

If so, they will explain the procedure for sending an electronic invoice.

If not :

  • Choose another accounting software. You will find here a (not exhaustive) list created by the Flemish Region and which includes accounting suppliers that allow the sending of electronic invoices via the Peppol network: list of accounting software
  • You also have the option of manually encoding your invoice via the Mercurius online portal (more information below).

You do not use an accounting and invoicing software

If you do not send many invoices to public administrations, you can use the Mercurius portal free of charge:

  • Link to portal: Mercurius portal
  • Access to the portal:
    Are you a legal representative of your company? Then you should have direct access to the Mercurius portal by default.

Are you not a legal representative but you want to encode invoices on behalf of your company? In this case, you will need to request access via the “Role Request” online form available on the Mercurius portal.

For more information on how to access, click here or contact the Mercurius helpdesk directly

In the portal, you can manually enter the different fields of the invoice (customer details, invoice number, due date, payment reference, invoice lines, etc.) and also attach an appendix (PDF, Word, etc.). By clicking ‘Send’, your invoice will automatically be sent to your customer in electronic format.

  • If you have any questions about the status of your invoice, go to the Mercurius help page or contact your client’s accounting department directly.

In the long run, to avoid manually encoding your invoice or if you regularly send invoices to public administrations, we recommend that you look for accounting software that allows the sending of electronic invoices via the Peppol network.

You will find here a list created by the Flemish Region and which includes different accounting suppliers: list of accounting software


Which administrations can receive electronic invoices?


In principle, all public administrations in the Brussels Region are able to receive electronic invoices.

Click here to find the contact details you can use to send an electronic invoice to the main local and regional administrations in Brussels.


Need help?


  • Do you have a question about the Mercurius portal, how to access it or how to enter an invoice?
    Contact the Mercurius helpdesk directly
  • Do you have a question about paying your invoice or the status of your invoice?
    Contact your client’s accounting department
  • If you have any other questions about electronic invoicing, please see our guide to electronic invoicing.
    The easy.brussels team is also available at [email protected]

You are an administration  


Implementing electronic invoicing in your administration


Discover the key steps to successfully adopting e-invoicing, as outlined on the Public Procurement website.


How do you inform your suppliers about electronic invoicing?


easy.brussels has designed various support documents to help you communicate with your suppliers, which you will also find in the useful documents at the bottom of the page:

Info-sessions for administrations


easy.brussels holds information sessions two to three times a year for the administrations.
Please contact us at [email protected] to find out when the next information session will be held or to receive a recording of a previous session.


Need help?


If you have any questions, please contact easy.brussels via the email address [email protected]

Statistics in the Brussels Region


  • Evolution of the number of electronic invoices received by the main Brussels regional public administrations since the launch of the project end 2020 :

  • Progress in the rate of electronic invoicing (volume of electronic invoices received in relation to the total volume of invoices received through all channels) in the Brussels regional public administrations:

Source: SPF/FOD BOSA (Mercurius), SAP and Brussels administrations Calculations by easy.brussels – figures for the main regional administrations and public interest bodies of the Brussels Capital Region