Belgium's employment law has undergone a significant overhaul. A package of legislative amendments to Belgian employment legislation took effect in early 2025, directly altering the obligations of foreign employers who post workers to Belgium. Maintain Belgian entities. Alternatively, engage local staff through cross-border arrangements. Companies that assume Belgian employment law remains unchanged risk non-compliance penalties and exposure to retroactive social security claims.
Belgium's updated employment legislation introduces revised rules on employment contract terms, dismissal notice periods, collective agreement obligations, and social security registration for foreign employers active in Belgium. The changes apply to all entities – domestic and foreign – employing or posting workers in Belgian territory. Businesses must review and update their employment contracts and internal HR procedures to reflect the new requirements without delay.
This alert outlines exactly what changed, which business categories are affected, and the immediate actions international companies should take now.
What changed – the regulatory developments and their effective dates
Belgium's revised employment legislation introduced four interconnected changes. Each carries its own compliance deadline and affects foreign employers in distinct ways.
Revised dismissal notice periods. The dismissal notice calculation rules under Belgian employment legislation were updated. Notice periods for higher-earning employees have been extended. For fixed-term employment contract holders, the termination procedure now requires written justification in a broader set of circumstances than previously applied. The revisions took effect on January 1, 2025.
Collective agreement obligations expanded. The scope of mandatory collectieve arbeidsovereenkomst (collective agreement) application was broadened. Foreign employers seconding workers to Belgium under a service provision arrangement must now verify whether a sectoral collective agreement applies – even where the Belgian engagement is short-term. This applies retroactively to secondments ongoing as of the effective date.
Social security registration thresholds lowered. Amendments to Belgian social security legislation reduced the threshold at which a foreign employer must register with Belgian social security authorities. The previous de minimis exemption for brief postings was narrowed. Employers relying on the prior threshold to avoid Belgian social security obligations should treat that position as no longer reliable without a fresh assessment.
Employment contract documentation requirements tightened. Belgian employment legislation now requires that all employment contracts – including those for posted workers – be provided to employees in writing before the first day of work. Digital delivery is recognised, but the specific format and language requirements depend on the region in which the work is performed: Brussels, Flanders, or Wallonia each maintain distinct language rules under Belgian federal structure.
For companies with Belgian corporate structures, these changes interact directly with board-level HR obligations and director liability exposure under corporate legislation.
Who is affected – threshold criteria and business categories
The updated rules apply broadly. The following categories of foreign employer face material compliance obligations:
- Companies posting workers to Belgium under intra-group service arrangements, even for short durations
- Foreign entities with Belgian-registered branches or subsidiaries employing local staff
- Non-EU employers providing services in Belgium through Belgian-based contractors or agents
- International groups whose Belgian operations are governed by a sectoral collective agreement – whether or not the employer is a signatory
- Employers using fixed-term employment contracts for Belgian-based roles who have not reviewed termination procedure documentation since 2024
The social security changes are particularly acute for employers in professional services, IT, construction. Additionally. Logistics. sectors where short-term postings are common and where Belgian sectoral collective agreements impose specific wage floors and working condition requirements.
In practice, a foreign employer that previously relied on an informal assessment of Belgian social security exposure now needs a documented legal position. The Rijksdienst voor Sociale Zekerheid (National Social Security Office of Belgium) has signalled closer scrutiny of cross-border arrangements following the 2025 amendments.
To receive an expert assessment of your Belgian employment obligations as a foreign employer, contact us at info@ferrazwhitmore.com.
What to do now – immediate actions and compliance timeline
International companies active in Belgium should take the following steps without delay. Failure to act before the applicable deadlines creates retroactive liability exposure under Belgian employment and social security legislation.
1. Audit all existing employment contracts. Review every employment contract governed by Belgian employment legislation. Confirm that notice periods, termination procedure clauses, and fixed-term provisions reflect the 2025 amendments. Contracts signed before January 1, 2025 may require addenda.
2. Identify applicable collective agreements. Map each Belgian operational unit or posting arrangement to the relevant sectoral collective agreement. Do not assume that a prior determination remains valid – the broadened scope of mandatory application may pull in arrangements previously considered exempt.
3. Reassess social security registration status. Any foreign employer relying on a pre-2025 threshold analysis for Belgian social security should obtain a fresh legal opinion. The cost of voluntary registration is substantially lower than retroactive contribution assessments and penalties.
4. Verify employment contract delivery compliance. Confirm that all employees working in Belgium received their employment contract in writing – and in the correct regional language – before their first working day. Where this cannot be confirmed for existing staff, consider remedial steps now rather than waiting for an inspection.
5. Brief your HR and payroll teams. The Belgian changes require operational adjustments across HR documentation, payroll calculation, and termination procedure workflows. Teams accustomed to the pre-2025 position need updated guidance before the next employment event triggers a compliance gap.
Companies managing employment matters across multiple jurisdictions may also find it useful to review our parallel regulatory alert on employment law changes in Portugal, where comparable posting and social security reforms are also in effect.
For a tailored compliance review of your Belgian employment position, reach out to our employment law team at info@ferrazwhitmore.com.
About Ferraz & Whitmore
Ferraz & Whitmore is an international law firm based in Lisbon, advising business clients across 46 jurisdictions. Our employment law practice assists international companies – including foreign employers active in Belgium – with employment contract drafting, collective agreement compliance, termination procedure management, and social security registration obligations. Engaging a lawyer in Belgium with cross-border employment experience is essential when regulatory changes interact with multi-jurisdiction HR structures. As an international law firm in Belgium and across Europe, we combine Portuguese civil law expertise with English common law tradition to deliver results-oriented counsel. Our attorneys have advised on employment and labour matters across both civil law and common law systems, including matters before Belgian administrative and judicial authorities. To discuss your situation, contact us at info@ferrazwhitmore.com.
Disclaimer: This publication is provided for informational purposes only and does not constitute legal advice. The information herein should not be relied upon as a substitute for professional legal counsel tailored to your specific circumstances. Ferraz & Whitmore assumes no liability for actions taken or not taken based on the contents of this material. For advice regarding your particular situation, please contact info@ferrazwhitmore.com.