Any natural person who exercises a professional activity in Belgium for which they are not bound by a contract of employment or a status is considered as a "self-employed person". There is no subordinate relationship.

As a self-employed person, you benefit from your own social status and a specific social security regime. As such, you must join a social insurance fund for self-employed persons of your choice and pay quarterly social security contributions.

Affiliation with a social insurance fund for the self-employed

Affiliation as a self-employed person

As a self-employed person, you must join the social insurance fund for self-employed persons of your choosing. This obligation also applies to people who are self-employed as their side activity.

You must join before the beginning  of the actual start of your self-employed activity.

If you do not meet the deadline, the National Institute for the Social Security of the Self-employed (NISSE) will ask you to regularise your situation. If you overlook this formality, you will automatically be affiliated to the National Auxiliary Fund for the Self-Employed.

Administrative fines are provided for in the event of infringement.

At the time of affiliation, non-EU nationals must be in possession of a professional card (which can be issued via the Belgian diplomatic or consular post in your country of residence or the enterprise counter of your choice).

Affiliation as a company

If you set up a company, you must also register it with a social insurance fund for the self-employed (even though you are already registered with it for your own account) within three months of setting up the company. An annual contribution will have to be paid to the social status for self-employed persons.

Payment of social contributions

As a self-employed person, you have to pay social security contributions to your social insurance fund. Under certain conditions, certain taxpayers are not required to pay social security contributions (people self-employed as a side activity, pensioners, students, etc.).

If you are a starting self-employed person as the main activity who has never worked as a self-employed person before or who stopped working as a self-employed person more than 5 years ago, you also have the possibility during the first four quarters of your activity to benefit from a reduced contribution scheme "primo starter", under certain conditions. 

Social security contributions are calculated in two phases:

  • in the contribution year itself, a provisional contribution is levied on the basis of the professional income of a self-employed person from three years ago. At the start of each quarter (in January, April, July and October), you will receive a notice of due date from your social insurance fund stating the amount of the provisional quarterly contribution due;
  • As soon as the tax authorities determined your final professional income (in principle two years later), the social insurance fund will draw up a final statement of social security contributions based on your professional income in the contribution year.

What about starters?

As a starter, you do not have a base year. Your provisional contributions are, then, calculated on the basis of an income that you provide yourself or on the basis of a statutory minimum.

Estimating your income

It is possible that the amount of your professional income three years ago does not correspond to your current professional income. Based on your contribution payment request, you must, therefore, make an estimate of your current self-employed income and compare it with income from three years ago.

Depending on the result, there are three possibilities:

  • your income remained more or less stable or you have difficulty estimating its evolution: you pay the contribution as indicated on the contribution payment request;
  • you estimate that your current income is higher than three years ago: you pay more contributions;
  • you find that your current income is lower than it was three years ago. Moreover, the income will most likely be below legally established thresholds. You may, then, be able to get a reduction (at the relevant threshold) in your provisional social security contributions. You must, however, demonstrate with supporting documents to your social insurance fund that your income fell or will fall during the contribution year concerned, as it must give its approval.

Please note! If, at the time of the final statement of contributions, your income is higher than the applicable threshold, the contributions still due will be increased.

Final statement

As soon as the social insurance fund is aware of the final annual income, it sends a final statement with the final amount of contributions. If you paid less, you will be charged extra. If you overpaid contributions, you will be refunded.

No increase is applied to the contributions still due, except for a self-employed person who unduly obtained a reduction.

More information?

For more information on the social status of self-employed workers and their rights and obligations, please contact the following bodies:

Federal Public Service Social Security
General-Directorate Legal expertise (self-employed) - Expertise juridique (Travailleurs indépendants)
Administrative Centre Botanique
Finance Tower 
Boulevard Jardin Botanique 50 box 135
1000 Brussels

Tel.: +32 2 528 64 50
Fax: +32 2 528 69 77
Website of the FPS Social Security

National Institute for the Social Security of the Self-employed (NISSE)
Quai de Willebroeck, 35
1000 Brussels

Tel.: +32 2 546 42 11
Fax: +32 2 511 21 53
Website of the NISSE

List of social insurance funds for the self-employed

Last update
14 November 2022