Social Contributions Guide for Belgian Self-Employed (2026)

What are social contributions?

Social contributions (sociale bijdragen) are mandatory quarterly payments that every self-employed person in Belgium must make to their social insurance fund (sociaal verzekeringsfonds). These contributions fund your social security coverage, including your pension, healthcare, child benefits, and disability insurance.

Whether you work as a full-time self-employed (zelfstandige in hoofdberoep) or as a self-employed secondary worker (zelfstandige in bijberoep), you are required to pay social contributions. The amount depends on your net taxable income and your employment status.

The 20.5% rate on net income

The standard rate for social contributions in Belgium is 20.5% of your net taxable professional income. This is calculated on your income after deducting professional expenses but before personal income tax. The social insurance fund calculates the final amount based on your actual income, which is typically known two to three years after the income year.

In the meantime, you pay provisional contributions based on either the legal minimum or an estimated amount. Once your actual income is confirmed by the tax authorities, a regularisation takes place and you may owe more or receive a partial refund.

Minimum contributions: bijberoep vs. hoofdberoep

The minimum quarterly contributions differ significantly between self-employed secondary workers and full-time self-employed:

• Bijberoep (secondary self-employed): approximately €88 per quarter (€352 per year). This is the minimum you must pay even if your calculated contribution would be lower.
• Hoofdberoep (full-time self-employed): approximately €867 per quarter (€3,468 per year). This minimum applies regardless of your actual income level and ensures full social security coverage.

The €1,900 exemption for bijberoep

If you work as self-employed in bijberoep and your annual net taxable income is below €1,900, you can apply for an exemption from social contributions. If granted, you pay €0 in social contributions for that year. This exemption is not automatic: you must actively request it from your social insurance fund and provide proof of your low income.

Keep in mind that if your income exceeds €1,900 during the year, you will owe the standard 20.5% on your entire net income, subject to the minimum quarterly contribution of €88.

Practical examples

Example 1: Bijberoep earning €500/year net

Annual net income: €500. Since this is below the €1,900 threshold, you can apply for an exemption. If approved, you pay €0 in social contributions.

Example 2: Bijberoep earning €2,000/year net

Annual net income: €2,000. This exceeds the €1,900 exemption threshold, so you owe social contributions. Calculation: 20.5% × €2,000 = €410 per year, or €102.50 per quarter. Since €102.50 is above the quarterly minimum of €88, you pay the calculated amount of €102.50 per quarter.

Example 3: Hoofdberoep earning €30,000/year net

Annual net income: €30,000. Calculation: 20.5% × €30,000 = €6,150 per year, or €1,537.50 per quarter. Since this exceeds the quarterly minimum of €867, you pay the calculated amount of €1,537.50 per quarter.

When and how do you pay?

Social contributions are paid quarterly to your social insurance fund (sociaal verzekeringsfonds). The deadlines are:

• Q1: due before April 1
• Q2: due before July 1
• Q3: due before October 1
• Q4: due before January 1 of the following year

You must be affiliated with an approved social insurance fund. In Belgium, there are several to choose from, including Acerta, Liantis, Xerius, and others. Your social insurance fund handles the calculation, collection, and administration of your contributions.

Important notes on rates (2026)

The rates and minimums mentioned in this article are based on Belgian RSVZ/INASTI guidelines as of 2026. These amounts are indexed and can change from year to year. Always verify the current rates with your social insurance fund or on the official RSVZ website.

How Bijzo helps

Bijzo automatically estimates your social contributions based on your tracked income and expenses. Throughout the quarter, you can see a real-time projection of what you will owe. Key features include:

• Automatic estimation: Bijzo calculates your expected social contributions based on your current net income.
• Quarterly tracking: see at a glance how much you should set aside each quarter.
• Exemption toggle for bijberoep: if your income is below €1,900, Bijzo shows you that you may qualify for an exemption and adjusts the projection accordingly.