Summary (3 bullet points)
- The Belgian tax authorities have published updated administrative guidance in Fisconet clarifying the application of the special tax regime for incoming researchers following legislative amendments effective 1 January 2025.
- The guidance confirms expanded tax-free employer cost allowances, adjusted eligibility conditions, and consistency with the broader framework for inbound personnel.
- Practical clarification is provided on qualifying researchers, calculation of tax-free allowances, supporting documentation, and payroll withholding obligations.
Article
The Belgian Federal Public Service Finance has published updated administrative guidance in Fisconet concerning the special tax regime for incoming researchers. This guidance reflects the changes introduced by the Law of 18 December 2025, which amended the Belgian framework for inbound researchers with effect from 1 January 2025 and applies to remunerations paid or granted as from that date.
Scope and Purpose of the Special Tax Regime for Incoming Researchers
The special tax regime for incoming researchers aims to support Belgian employers—particularly in research-intensive sectors—in attracting highly qualified foreign researchers. Under this regime, employers may grant certain allowances as tax-free reimbursements of costs specific to the employer, in addition to the contractual remuneration. The administrative guidance confirms that the regime applies both to researchers recruited directly from abroad and to those seconded to Belgium within multinational groups, provided all statutory conditions are met.
Key Clarifications from the Tax Authorities
The guidance provides detailed clarification on the practical application of the special tax regime for incoming researchers, including:
- Eligibility conditions: Incoming researchers must not have been subject to Belgian income tax nor have resided within 150 km of the Belgian border during the five years preceding the start of their Belgian activities. Nationality is irrelevant when assessing eligibility.
- Tax-free allowances: Employers may reimburse recurring costs tax-free up to 35% of the researcher’s gross annual remuneration, reflecting the increase from 30% and the abolition of the former annual ceiling of EUR 90,000.
- Exceptional expenses: Certain one-off costs—such as relocation expenses, housing set-up in Belgium, and school fees—may also qualify for tax-free reimbursement, subject to appropriate substantiation.
Administrative and Payroll Implications
The tax authorities emphasise that employers are responsible for the correct payroll application of the special tax regime for incoming researchers, as well as for maintaining adequate documentation and monitoring continued compliance with the eligibility conditions throughout the duration of the regime. Where the conditions are no longer met, the tax advantages must be discontinued on a prospective basis. The guidance also recalls the importance of timely applications and annual follow-up, particularly where the researcher qualifies as a non-resident for Belgian income tax purposes.
Practical Relevance for Employers
This administrative publication provides welcome legal certainty on the operation of the revised special tax regime for incoming researchers. For multinational groups and Belgian employers active in research and development, the clarified positions facilitate compliant implementation, payroll alignment, and audit readiness when applying this regime in practice.
Source: MyMinfin
