Subcontracting: Are Your Contracts Legally Up to Date?

A subcontracting agreement does more than govern the commercial aspects of a business relationship. It must also take account of important requirements under employment and social security law.

Here are three practical examples:

1. What instructions can you give directly to your subcontractor’s employees?

Belgian law strictly regulates this issue. Beyond instructions relating to health, safety and well-being at work, any instructions that a client may give to a subcontractor’s employees must, in particular, be expressly and specifically set out in a written agreement, without undermining the subcontractor’s authority as their employer.

Furthermore, the way in which the parties actually work together must reflect the provisions of the agreement.

Otherwise, the arrangement risks being classified as the unlawful provision of workers to a third party.

In practice, we still regularly encounter agreements that are too vague on this point or no longer reflect operational realities.

One practical solution may be to establish a framework agreement, supplemented by individual statements of work specifying the services to be performed and the instructions that may legitimately be given.

Legal basis: Article 31 of the Belgian Act of 24 July 1987 concerning the provision of workers to third parties.

2. How far can the subcontracting chain extend?

Since 1 January 2025, additional rules have applied, particularly in the construction, removals and meat sectors.

In these sectors, subcontractors are no longer permitted to subcontract the entire performance of their contractual obligations to another subcontractor. They are also prohibited from retaining responsibility solely for coordinating the performance of the contract.

In certain sectors and for certain contracts, the subcontracting chain may also be limited to three tiers.

These rules form part of the legislator’s efforts to combat fraud and social dumping, while improving transparency throughout subcontracting chains.

Legal basis: Articles 147 and 148 of the Belgian Act of 15 May 2024 concerning subcontracting.

3. Does your subcontractor have outstanding debts?

For certain activities, particularly construction-related works and activities in the meat sector, engaging a subcontractor also entails verification obligations and, where applicable, requirements to withhold part of an invoice payment.

Before making certain payments, businesses must check whether their contracting party has outstanding social security or tax debts.

Where such debts exist, a portion of the invoice amount must be withheld and paid directly to the competent authorities.

Failure to comply with these obligations may, among other consequences, result in joint and several liability for the contracting party’s debts.

Legal basis: In particular, Articles 30bis and 30ter of the Belgian Act of 27 June 1969 concerning workers’ social security, and the corresponding provisions of the Belgian Income Tax Code 1992.

Of course, many other legal considerations may arise when structuring a subcontracting relationship.

These examples illustrate a common trend: subcontracting relationships and chains are subject to increasingly stringent legal requirements and closer scrutiny.

A coordinated approach to the commercial, contractual and employment law aspects of subcontracting helps businesses establish robust, fit-for-purpose agreements that genuinely reflect how the relationship operates in practice.

Our firm also has the expertise required to advise and support businesses on these specific aspects of their subcontracting relationships.

Do you have questions about the employment and social security implications of subcontracting, or need to review your standard contractual documentation?

Get in touch with us.

Bertrand Wittamer
Partner

Tanguy Gillain
Employment Partner