New rules for registering EU workers as of 1 September 2025

EU nationals who are posted to Belgium are required to register at their Belgian municipality. From 1 September 2025, there is a significant change in the procedure for applying for a proof of registration.

Whereas previously applicants had three months (plus possibly one extra month) to submit missing documents, as of September employees will have to submit all documents immediately. There will be no more exceptions: anyone who does not submit all the required documents will not be able to start the application process.

What changes?

• Up until the 31st of August 2025: An employee could register with the local authority and submit missing documents up to 3 months later.
• As of 1 September 2025: All required supporting documents must be submitted immediately with the initial application. If anything is missing, the application will be rejected immediately.

Example

A Polish employee is posted to work in Antwerp. Until recently he could register with an employment contract and submit additional documents later. As of September 2025, he must ensure that all documents are available at the first visit to the service desk – for example, proof of employment and proof of health insurance.

Important for employers

The Belgian law has a strict list of accepted supporting documents. Although EU law allows more leeway, local authorities often refuse anything that does not precisely match the official list. This can cause problems with, for example, alternative contract forms or atypical supporting documents.

Advice

• Prepare the registration before leaving for Belgium.
• Ensure that your employee has all the required documents with them from day one.
• It is best to contact the receiving municipality in advance to check their interpretation of the list.
• If possible, schedule the first visit to the municipality immediately after arrival to avoid delays.

In practice

We have noticed that Belgian contractors increasingly expect that all employees of foreign subcontractors, whether they are EU citizens or non-EEA nationals, register with the municipality immediately after arrival and provide them with proof of their registration. This is undoubtedly being done in the context of the upcoming due diligence obligation, which will come into force on 1 January 2026. In other words, correct registration with the local authority is certainly not a useless exercise, as many still believe.