What are social security contributions?

As a self-employed person, you have to pay quarterly social contributions. But what exactly are social contributions? Why do you have to pay them? And how are they calculated? You'll read it here. 

So, what are those social contributions? 

In Belgium, anyone working has to pay social contributions. But unlike employees, whose social contributions are deducted from their salaries, self-employed people have to pay them themselves. 

Your social contributions represent a legal percentage of 20.5% of your "annual net taxable professional income", calculated by the tax authorities. Regardless of your status as a self-employed person (company, natural person, self-employed as a primary or secondary activity), you are obliged to pay contributions to a social insurance fund. The payment of these contributions guarantees your social rights (state pension, healthcare, child benefits, bridging rights, etc.). 

How are social security contributions calculated?  

Your social contributions are calculated based on your income. This is a provisional calculation, as it is based on your income from 3 years earlier. This gross amount is reduced by: 

  • Your business expenses  

  • The social security contributions already paid 

  • The contributions you pay for your supplementary pension 

When calculating your personal social security contributions, other factors also come into play, such as your self-employed status. Your accountant can give you more details. 



When the tax authorities send your social insurance fund your actual income, 2 or 3 years later, the fund calculates your final social contributions. You will then receive a regularisation: either we will charge you a supplement, or we will refund the surplus you paid. If the difference between your contributions and your actual income is too large, it's worth optimising your contributions.

Depending on your status, different ceilings apply: 

As a starting self-employed person

During the first 3 calendar years of your business, you can pay a minimum flat-rate amount each quarter. And if you (or your accountant) can estimate that your income will be higher than the minimum forfeit, you could pay a fixed amount.  

As an established self-employed person

If you have been self-employed for more than 3 years, you are subject to the 'definitive system'

Social security contributions represent a percentage of your net taxable income, determined based on set income scales: 

  • From the 4th year onwards: 20.5% of net taxable income 

  • Proportion of income exceeding €63,297.86 per year: 14.6% 

  • Proportion of income exceeding €93,281.02 per year: no additional social security contributions 

  • Added administrative costs: 4.25% of the amount of social contributions 

When to pay social contributions?  

Every quarter, you pay your social contributions to your social insurance fund. As an entrepreneur, you have until the end of the current quarter to pay the full amount. Tax quarters start on 1 January, 1 April, 1 July and 1 October each year, respectively. 

Some good advice? 

"Pay your contributions no later than:

  • On 21 March (contributions 1st quarter) 

  • On 21 June (contributions 2nd quarter) 

  • On 21 September (contributions 3rd quarter) 

  • On 21 December (contributions 4th quarter) 

Some very good advice? 

Pay by direct debit. You can easily set it up in our online tool My Social Security Manager or through one of our colleagues. 

What if you can't pay the contributions?  

Facing financial difficulties? Any business owner can be temporarily struggling, and paying social security contributions on time can be too much of a burden. 

The first thing to do if you find yourself in this predicament is to contact Partena Professional immediately. Together, we will find a solution that protects your social security as much as possible.


Financial problems? Ask us about our solutions


Make your life easier with our online tool 


Our My Social Security Manager platform is simple and efficient. It allows you to access your social security file and carry out all kinds of transactions online:  

  • Create simulations  

  • Adjust your contributions  

  • Make payments  

  • Consult your documents   

  • Draw up career certificates  

  • Check your balance  

  • Get a payment plan and advice  

  • Ask your questions and get a guaranteed response within 48 hours  


Discover our online tool

Any other questions?
How to increase or decrease your social security contributions

If your income is higher than the one used to calculate your contributions, you can decide to increase your provisional contributions. This way, you can avoid having to pay an extra sum when your contributions are recalculated. Furthermore, it means you have to pay less taxes.  

If, on the other hand, your income is significantly lower than the one used to calculate your contributions, you can apply for a reduction of the provisional amount. 

How can you modify your contributions? Try our online tool My Social Security Manager to easily increase or decrease your social security contributions.    

Finally, if you have any questions about the amount of social security contributions you have to pay, try our simulator to quickly and easily calculate the amount you have to pay. 

Social security contributions for the self-employed: what are my rights?

The social security contributions you need to pay each quarter as a self-employed entrepreneur entitle you to basic social protection: 

  • Family allowance 

  • Birth grant and maternity benefit 

  • Health and invalidity insurance 

  • Statutory pension 

Bridging rights This means you benefit from social security rights and are prepared for a setback. Need a reminder of your rights and duties as an entrepreneur? Learn more about them on this page.  


Can I calculate my social security contributions?

You can calculate your social security contributions with our online simulator or My Social Security Manager. This will enable you to determine if the amount needs to be adjusted to avoid any unpleasant surprises at the time of regularisation.  

What do I do if I’m paying too much for my social security contributions?

Are you paying too much for your social security contributions? Not to worry: you can always apply for a reduction of your contributions, or the surplus you pay will be paid back to you when your contributions are regularised.  

What are the consequences if I don’t pay?

Be careful: if you don’t pay your social security contributions, you risk losing out on your social insurance and compensation for your family’s health care.  

Contact us before it comes to that or read our advice in case of payment issues! 

What are the penalties for late payment?

If you pay late, you will be charged with financial penalties: a 3% surcharge on the contributions that weren’t paid for each started quarter and a one-off additional surcharge of 7% if your contributions still haven’t been paid on 31 December. These surcharges and penalties are not tax-deductible. 

How can I optimise my social security payments and my taxes?

You can influence the calculation of your contributions and taxes by taking the amount of your professional expenses and that of your social security contributions into account: 

  • Pay more or less provisionary contributions. 

  • Use (intelligent) expenses to subtract them from your income and reduce your taxes and social security contributions. For example, bolster your social security with supplementary insurance policies that are tax-deductible: FSPSE and guaranteed revenue insurance are tax-deductible, for instance.  

  • Consider becoming a partnership 

  • Think about the right legal status of your company and take advantage of a more fiscally appealing model. 


Contact your accountant to find out which option is best for you. 

How can I find all the information about my social security profile?

Easily find all your information in your social security record and ask all your questions via our tool My Social Security Manager. You’re guaranteed to get a response under 24 hours!  

Some benefits of My Social Security Manager :  

  • Easily consult your file online, wherever and whenever you want  

  • Modify your data yourself  

  • Adjust the amount of your contributions  

  • Report a termination of activity  

  • Regularise your outstanding payments  

  • ... 

Which changes should I report?

Report any changes that may affect your social security record or will make you eligible for benefits and support. For example :  

  • Birth 

  • Starting an activity 

  • Changing your activity 

  • Termination of your activity 

  • Bankruptcy 

  • … 

Share these changes with us by email or through the contact page of our tool My Social Security Manager.