In our newsletter of 22 December 2025 we provided an overview of the changes to the special tax regime for inbound taxpayers and inbound researchers implemented retroactively since 1 January 2025 on a tax level.
The Belgian social security authorities just published interim instructions in which it is confirmed that these tax changes will for the time being not be fully implemented on a social security level.
It follows that there will be a difference in the tax treatment vs. the social security treatment of an inbound taxpayer or researcher provided that such a person is covered by Belgian social security.
This difference can be highlighted as follows:
| Tax | Social security | |
|---|---|---|
| Annual gross remuneration > € 70.000 | yes | yes |
| Cost allowance | 35% | 30% |
| Cap allowance € 90.000/year | no | yes |
It goes without saying that this difference triggers an additional layer of complexity for the payroll of an inbound taxpayer or researcher subject to Belgian social security.
It’s time to act!
E-mail tax@propay.be if:
- You would like more information about the special tax regime;
- You would like assistance with the preparation and submission of the (special) application for special tax regime;
- You would like assistance in relation to re-evaluating existing compensation packages and/or employment contracts.