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Social security

Belgium has a very extensive social security system. PhD students and postdoctoral grant holders with a grant contract, as well as researchers and professors with an employment contract,  are entitled to certain allowances and services.   

Each month, the employer must pay an amount on top of your salary into the social security fund (Belgian National Social Security Office (ONSS)). As an employee, you also contribute a proportion of your gross salary in social security contributions. This is mandatory and contributions are deducted at the source, meaning you won’t have to do anything for this yourself.

Taxes in Belgium

Whether you pay taxes depends on a number of criteria. International staff with an employment contract must complete an individual tax return if, on 1 January of the tax year in question, they:

  • are included in the National Register;
  • have their domicile or centre of financial interest in Belgium;
  • are not exempt from the requirement to submit a tax return.

Individual tax returns must be submitted annually to the department specified on the tax return.

Grant holders (PhD students and postdoctoral researchers) are not liable to income tax as individuals. Contact People & Organization for more information about tax exemption conditions for grant holders.


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