Construction in Belgium: new time-registration rules for 2027 and legal obligations for foreign subcontracting

Working with international partners is common practice in Belgium’s construction sector. However, Belgian legislation imposes strict requirements on local companies that use foreign subcontractors.

From the current ONSS procedures to the changes planned for April 2027 (Check In and Out at Work), here is what every Belgian contractor needs to prepare for.

The ONSS obligation for foreign subcontractors: from the very first euro!

Many Belgian companies are unaware that using a foreign subcontractor automatically triggers the obligation to submit a Declaration of Works (DDT) to the ONSS, Belgium’s National Social Security Office.

No minimum amount: as soon as a Belgian company assigns work to subcontractors, particularly within an international subcontracting chain, a prior declaration is mandatory from the very first euro.

The Belgian company’s responsibility: failing to declare a foreign subcontractor correctly exposes the main contractor to substantial financial and administrative penalties during social inspection checks.

What changes for site time registration from April 2027

Alongside the declaration of works, attendance monitoring is evolving towards Check In and Out at Work for sites worth €500,000 or more, excluding VAT:

Check-in AND check-out: everyone involved will have to register their arrival and departure every day.

On site and in real time: registrations made in advance from the office will no longer be accepted.

Individual registration: workers, self-employed professionals and subcontractors will have to register themselves using a QR code, smartphone or badge.

Why audit your processes now?

Bringing your contracts into compliance, checking that your foreign subcontractors are registered with the ONSS and adapting your site tools requires advance planning.

Incorrect or missed procedures can bring a construction site to a halt or result in cumulative fines. Specialist support is strongly recommended to safeguard your contracts and statutory declarations.