A well-known phenomenon within the construction sector in Flanders, and more broadly in Belgium, is the emergence of lengthy chains of contractors involved in the realization of a client's construction project. Main contractors work together with subcontractors, who in turn collaborate with their own subcontractors, and so on. While such extensive chains of professionals are not necessarily problematic, each link in the chain must remain vigilant regarding its liabilities and responsibilities. This duty of vigilance has become even more stringent since the legislative reform concerning chain liability for the illegal employment of unlawfully residing third-country nationals entered into force on the 1st of January 2026.
- Scope of Application
The legislative reform applies to all business entities within the construction chain. Consequently, any company may be held liable, regardless of whether:
- it is a Belgian or foreign company;
- it operates directly or indirectly within the Flemish Region;
- it acts as the client, main contractor, or subcontractor within the chain.
This broad scope of application is intended to ensure effective oversight of the engagement of self-employed persons and employees from third countries, namely Switzerland or countries outside the European Economic Area (EEA). Through this legislation, the legislator aims to combat the practices of unscrupulous contractors and promote fairer competition within the sector.
The due diligence obligation (see below) does not apply when:
- the construction works amount to less than EUR 30,000.00 (excluding VAT) and are carried out by a contractor without any subcontractors; or
- the construction works amount to less than EUR 5,000.00 (excluding VAT) and involve no more than one subcontractor.
- A Duty of Due Diligence
One mechanism for avoiding liability within the chain is to comply with your duty of due diligence as a prudent and diligent contractor or client. This obligation entails the following:
- You must request the necessary documents in advance from your direct (sub)contractor (Article 79/1 of the Decree of the Flemish Government implementing the Act of 30 April 1999 on the employment of foreign workers), which should demonstrate that no illegally residing third-country nationals are being employed.
- You must obtain a written declaration in which your direct (sub)contractor confirms that it does not employ, and will not employ, illegally residing third-country nationals as employees or self-employed workers.
- You must verify the authenticity and validity of the documents received.
- You are required to retain these documents for a period of five years after the termination of the collaboration.
- In the event of missing or falsified documents, the relevant party within the chain must address the issue with the concerned (sub)contractor, remind them of their obligations and, where appropriate, report the matter through the reporting platform of the Flemish Social Inspection Service.
Only by fulfilling these obligations can you avoid chain liability.
- Transitional Arrangements
The Flemish Government has introduced a six-month grace period to allow contractors and project owners sufficient time to adapt to the new regulations. As of 1 July 2026, fines will effectively be imposed for infringements of these rules.
Chain liability in the construction sector entails significant obligations and risks for both project owners and contractors. A proactive approach and proper legal screening of your business partners can prevent many issues and liabilities. At Adverit Legal, we closely monitor legislative developments and assist entrepreneurs with practical and strategic advice. This allows you to focus on your construction projects while we safeguard your legal interests. Would you like certainty regarding your position within the contracting chain? We are ready to act as your trusted legal partner.
