Background
Since 2022, Belgium has a favourable tax regime for ‘inbound taxpayers’ (employees and company directors) and ‘inbound researchers’ who take up employment in Belgium. The regime allows certain employer-paid allowances to be treated as tax-free, making it particularly attractive for internationally mobile talent.
The legislation distinguishes between inbound taxpayers (BIBB), and inbound researchers (BBIO). To benefit from either regime, both the employer and the employee (or company director) must meet a number of statutory conditions. We have covered this on several occasions in previous articles; you can find them here and here.
In December 2025, the Belgian legislator adopted a series of amendments aimed at further strengthening Belgium’s position in the international competition for talent. Although the changes were already announced at the beginning of 2025, they were only incorporated into legislation recently. These changes apply, from a tax perspective, retroactively to qualifying remunerations paid or granted as from 1 January 2025.
Lower minimum remuneration threshold
One of the key changes concerns the minimum remuneration threshold applicable to inbound taxpayers (not to researchers). Under the original rules, the employee or company director was required to receive a gross annual remuneration exceeding €75,000. As from income year 2025, this minimum threshold is reduced to €70,000 per calendar year. As a result, a broader group of employees and company directors may now qualify for the regime, provided that all other statutory conditions are met.
At the time of filing the application, the reference gross remuneration is the annual gross remuneration for services performed in Belgium that is certain and fixed at that moment. Variable bonuses or benefits that are still subject to future conditions cannot be included, whereas bonuses that are guaranteed and unconditional may be taken into account. In the case of a salary split, the minimum threshold applies only to the remuneration attributable to services performed in Belgium.
The minimum remuneration threshold is subsequently assessed on the basis of the actual gross remuneration effectively earned for Belgian activities, including bonuses and benefits effectively received. This assessment is carried out after the end of each year in which the expat tax regime applies.
Transitional application for employees hired in 2025
A transitional measure applies to employees and company directors who took up employment in Belgium between 1 January 2025 and the 10th day following the publication of the amending legislation in the Belgian Official Gazette, which is 9 January 2026.
Individuals whose annual gross remuneration falls within the €70,000 to €75,000 range, and who therefore did not meet the former threshold, may still submit an application for the inbound taxpayers regime. The application must be filed within a strict deadline of 3 months, calculated as from 9 January 2026, meaning that applications must be submitted no later than 9 April 2026. Late submissions will not be accepted.
Increase of tax-free expense allowance
A second important amendment concerns the lump-sum tax-free reimbursement of recurring expenses linked to employment in Belgium. Under the former rules, the tax authorities accepted a tax-free allowance of up to 30% of the gross remuneration, subject to an absolute cap of €90,000 per year.
Under the amended legislation the maximum percentage has been increased from 30% to 35%, and the €90,000 cap is abolished. This improvement applies to both inbound taxpayers (BIBB) and inbound researchers (BBIO) and is also applicable to remunerations paid or granted as from 1 January 2025.
Although referred to as a 35% expat allowance, the exemption is effectively lower when assessed against the total remuneration package. Since the allowance is calculated on top of the base salary, it corresponds in practice to approx. 26% of the overall remuneration. By way of example, where a total gross remuneration package amounts to €100,000, the exempt amount is not €35,000, but €25,925.93 (i.e. €100,000 / 1.35 × 35%). As such, the label ‘35% allowance’ can be misleading, as it overstates the effective level of exemption when viewed in relation to the total compensation.
Social security position (NSSO)
While the tax treatment has become more favourable, the social security position has not (yet) been aligned. In interim administrative instructions dated 22 December 2025, the National Social Security Office (NSSO) confirmed that, for social security purposes, the existing rules remain unchanged. In practice, this means that:
- the exemption from social security contributions continues to be limited to 30% of the remuneration, and
- the €90,000 cap remains applicable for social security purposes.
Consequently, the additional 5% allowance, although fiscally exempt, may still be subject to social security contributions, both for the employee and the employer.
At this stage, there appears to be no substantive rationale for applying a different treatment for social security purposes than for tax purposes. Moreover, this divergence further complicates payroll calculations. Many payroll providers were already facing practical difficulties in correctly implementing the tax-free allowance under the previous rules, and the introduction of a split tax/social-security treatment only increases operational complexity.
What does this mean for employers?
From an employer’s perspective, the amended legislation creates additional opportunities to optimise the income tax position of foreign executives and inbound company directors. A careful, case-by-case assessment of both the tax and social security implications remains essential when applying the inbound taxpayers or inbound researchers regime.
Within the contractual boundaries of the employment agreement and the agreed remuneration package, it may therefore be advisable to review existing applications with a view to potentially increasing the expat allowance and maximizing the available tax benefits under the revised framework.