Starting out as a self-employed person: your social security obligations

Do you want to become self-employed? In that case, you will have to complete some administrative procedures for your social security.

Before starting your self-employed activity, you must join a social insurance fund for self-employed persons of your choice.

In case you don't join a social insurance fund, the National Institute for the Social Security of the Self-employed (NISSE) will send you a reminder, giving you 30 days to join one.

If you haven't joined a fund by the end of this 30 day period, you will automatically become a member of the National Fund.

If you do not join in time, you may have to pay an administrative fine.

If you are setting up a company, the company must also join within 3 months of start-up (even if you already joined yourself).

As a self-employed person, you must pay social security contributions to accrue entitlements (pension, sickness insurance, etc.).

How much?

Your social security contributions are a percentage of your net taxable earnings from self-employment for the year in which you are paying contributions. There is a minimum contribution.

Since your income is not yet known when the contributions are paid, they are calculated in two stages:

  • You pay provisional contributions in the contribution year itself, based on your income from 3 years ago.
  • Once your income for the contribution year is known, your social insurance fund converts your provisional contributions into final contributions; this means you will either have to pay extra, or you will get a refund.

Some categories of self-employed persons (those for whom self-employment is a subsidiary occupation, retired persons, students, start-ups, etc.) pay lower contributions, and sometimes even none at all, if their income remains limited.

When and to whom?

You pay the contributions to the social insurance fund every quarter. You also pay an administration fee.

Companies pay an annual contribution, which is reserved for the social security scheme for self-employed persons.

As a self-employed person, you are obliged to join a health insurance fund (in French)  when you join a social insurance fund. This entitles you to sickness and disability insurance. You can find out more about this at NISSE (in French).


You should report any changes in your work situation (for example a change from full-time self-employment to self-employment as a subsidiary occupation) or your family situation (for example divorce) to your social insurance fund.

You can find out more about the other administrative formalities to be completed when starting out as a self-employed person (such as registering with the Belgian Central Enterprise Databank, taxobligations, hirin staff, etc.) at:

More information about the requirements for starting out as a self-employed person in Belgium on the starting as a self-employed person page of the FPS website.