Belgium eases the Special Tax Regime for Incoming Taxpayers and Researchers as of 1 January 2025

Belgium has officially enhanced its Special Tax Regime for Incoming Taxpayers and Researchers. The amending law was published in the Belgian Official Gazette on 30 December 2025, confirming the changes applicable to allowances granted as from 1 January 2025.

The new measures increase the tax-free allowance, abolish the annual cap and lower the salary threshold, making the regime more attractive for international recruitment and mobility.
 

AT A GLANCE — WHAT IS CHANGING?

• Tax-free lump sum (costs proper to the employment): increases from 30% to 35% of gross annual remuneration.
• Annual cap on the tax-free lump sum: €90.000 cap is abolished.
• Minimum salary for incoming taxpayers (not applicable to researchers): reduced from €75.000 to €70.000 gross per year.
• Researchers: still no minimum salary requirement, but the existing degree and time allocation conditions continue to apply.
• Application window & duration: the regime continues to apply for a period of five years, with the possibility of a three-year extension. A formal application must still be filed within three months following the start of employment in Belgium.

1. Why this matters

Since the 2022 reform, many employers found the rules too restrictive for international hiring. The new adjustments intend to rebalance the regime by increasing the available tax-free allowance and widening eligibility.
 

2. Position Belgian NSSO

The Belgian National Social Security Office (NSSO) does not agree with the changes proposed by the Belgian tax authorities. More specifically, it does not agree with increasing the rate from 30% to 35%, nor with abolishing the EUR 90.000 cap.

In practice, this means that Belgian employer and employee social security contributions will still be due on the 5% difference between 30% and 35%, as well as on any amounts exceeding the EUR 90.000 cap.
 

3. Practical calculation

For an employee earning a gross annual salary of EUR 100.000 and receiving a net cost allowance (cost proper to the employer, or CPE) equal to 35% of that salary, the salary breakdown would be as follows:

4. What employers can do now

• Identify impacted employees: 
  - Review current beneficiaries to determine whether the allowance can be increased from 30% to 35% and whether the cap removal creates additional tax-free room from 01.01.2025.
• Consider contract & policy adjustments: 
  - Where the allowance is referenced in contracts or policies, assess whether amendments are needed to implement the changes.
• Plan payroll updates: 
  - Prepare payroll and HR documentation to reflect the higher percentage and abolished €90.000 cap for allowances granted in 2025.
• Screen new hires & transferees : 
  - Reassess candidates around the €70.000 level and researchers who meet the diploma/time criteria.
• Prepare timely applications: 
  - Maintain the 3 month application timeline after start date and gather supporting documentation early.
   

5. New circular introduces deadline for retroactive amendments

A new circular published on 1 April 2026 confirms that employers may still amend existing employment contracts with retroactive effect as from 1 January 2025 in order to align with the new tax rules.  Such amendments may allow the employment agreement for to reflect the new fiscal thresholds, namely:

• for incoming tax payers, the annual gross remuneration may be reduced to minimum EUR 70.000 instead of minimum EUR 75.000;
• for both incoming tax payers and incoming researchers, the amount of costs proper to the employer may now amount to a maximum of 35% of the gross remuneration instead of 30%, without being subject to the annual cap of EUR 90.000.

At the same time, the Belgian tax authorities impose a clear deadline: such amendments must be made within three months following the publication of the circular and in compliance with applicable employment law.

Accordingly, the practical deadline for implementing these retroactive amendments is 1 July 2026.
 

HOW RSM CAN ASSIST 

• Recalculating allowances for existing beneficiaries and implementing changes in payroll
• Assessing eligibility for new hires, transferees and researchers and submitting applications
• Reviewing and rewriting employment contracts and internal policies
• Supporting employers with compliance and procedural deadlines

Partner with RSM Belgium and ensure that you and your employees maximize the opportunities provided by the special tax regime. Let our expertise guide your business to success in Belgium’s evolving tax landscape.

If you have any questions regarding this topic, don't hesitate to contact our RSM Belgium | Global Employer Services team (ges@rsmbelgium.be).