Indexo for expats
Salary after tax in Belgium: a guide for expats (2026)
Updated on
In Belgium, a single employee earning €4,500 gross a month takes home €2,831.86 net in 2026; with a partner who has no income and two children, €3,437.72. Three deductions take you from gross to net: social security contributions of 13.07%, withholding tax, and a small special social security contribution. Your family situation changes the withholding tax; your municipality changes your final tax bill.
Every salary amount in this guide is computed by Indexo’s engine with the rules in force on 1 October 2026. Nothing you type on Indexo is sent anywhere: the calculations run in your browser.
From gross to net in three steps
A Belgian payslip always follows the same order. Here is what happens to €4,500 gross a month for a single employee.
1. Social security contributions: 13.07%
Your share of social security (RSZ-bijdragen / cotisations ONSS) is 13.07% of your gross pay: €588.15 here. It is collected by the National Social Security Office (NSSO). On lower pay, a work bonus (werkbonus / bonus à l’emploi) reduces it by up to €299.53 a month; it disappears above €3,403.62 gross for a full-time employee. Your employer pays its own contributions on top, a basic 25% of your gross pay, which you will not see on your payslip.
2. Withholding tax: an advance on your income tax
Withholding tax (bedrijfsvoorheffing / précompte professionnel) is deducted every month and paid to FPS Finance: €1,035.98 here. The official formula takes your taxable pay over a year, removes lump-sum professional expenses (30%, up to €6,070 a year), applies rates from 26.75% to 53.50%, then deducts the tax-free amount (belastingvrije som / quotité exemptée) and the reductions for your dependants. It includes a flat 7% municipal surcharge.
3. Special social security contribution
A smaller monthly deduction (bijzondere bijdrage voor de sociale zekerheid / cotisation spéciale de sécurité sociale) that depends on your household’s income: €44.01 here, and at most €60.94 a month for a single person. It is recalculated in your tax assessment notice (aanslagbiljet / avertissement-extrait de rôle) with your household’s actual income.
| Monthly amount | €3,000 gross | €4,500 gross | €6,000 gross |
|---|---|---|---|
| Gross salary | €3,000.00 | €4,500.00 | €6,000.00 |
| Social security (13.07%) | −€392.10 | −€588.15 | −€784.20 |
| Work bonus | +€110.54 | €0.00 | €0.00 |
| Taxable pay | €2,718.44 | €3,911.85 | €5,215.80 |
| Withholding tax | −€474.50 | −€1,035.98 | −€1,688.22 |
| Fiscal work bonus | +€36.63 | €0.00 | €0.00 |
| Special social security contribution | −€19.24 | −€44.01 | −€60.51 |
| Net pay | €2,261.33 | €2,831.86 | €3,467.07 |
| Net as a share of gross | 75.4% | 62.9% | 57.8% |
The following year, your tax return settles the account. Your final tax depends on your whole year’s income, your household and the rate of your municipality; the difference with the withholding tax becomes a tax refund or tax to pay. Estimate your tax refund or tax to pay.
Why your net pay differs from a colleague’s
Two people on the same gross salary rarely take home the same amount. At €4,500 gross a month:
| Situation | Withholding tax | Special contribution | Net pay |
|---|---|---|---|
| Single, no children | −€1,035.98 | −€44.01 | €2,831.86 |
| Couple, two incomes | −€1,035.98 | −€39.85 | €2,836.02 |
| Couple, two incomes, two children | −€897.98 | −€39.85 | €2,974.02 |
| Single, two children | −€897.98 | −€44.01 | €2,969.86 |
| Couple, one income | −€572.28 | −€39.85 | €3,299.72 |
| Couple, one income, two children | −€434.28 | −€39.85 | €3,437.72 |
- Your household. If your spouse or legal cohabitant has no income (or very little), part of your income is attributed to them for tax, up to €13,790 a year in the withholding tax formula (the marital quotient). Each dependent child lowers your withholding tax.
- Your municipality. Municipalities (gemeenten / communes) add a surcharge to your income tax: 0% in Knokke-Heist, the lowest, up to 9% in Mesen, the highest, in tax year 2026. Your monthly pay assumes 7%; the real rate is applied in your tax assessment notice. See the rates of 10 Brussels municipalities compared.
- Your status. Blue-collar workers (arbeiders / ouvriers) pay social security on 108% of their gross pay and receive their holiday pay from a holiday fund; civil servants have their own rules.
- Your benefits. Meal vouchers, a telework allowance or a company car change your net. How common benefits are taxed.
- Your contract. If you were recruited abroad and earn more than €70,000 a year, the expat tax regime lets your employer pay a tax-free allowance of up to 35% of your gross pay. If you are posted by a foreign employer and stay insured at home (A1 certificate in the EU), no Belgian social security is deducted and the examples above do not apply.
Indexo for expats: the guides
- Your net salary on arrivalWorked examples from €3,000 to €6,000 gross, your first payslip, holiday pay in year one and your first tax return.
- The expat tax regime (inbound taxpayers)Who qualifies after the 2025 reform, the 35% allowance, the application deadline and a worked example.
- Your first-year checklistRegistration with your municipality, national register number, health insurance, family allowances, bank, insurance, driving licence, tax return and pension.
- Your Belgian payslip explainedEvery line, with the Dutch and French labels you will see, and what surprises newcomers.
Calculate your own net salary
Enter your gross salary, family situation and municipality in the Indexo calculator: it shows every line of your payslip, your holiday pay and your tax for the year.
For a quick answer, the gross-to-net table gives the net pay of eight common salaries.
Indexo gives information, not tax or legal advice. For your own case, your employer’s social secretariat (sociaal secretariaat / secrétariat social), which runs its payroll, FPS Finance or a tax adviser has the final word.
Frequently asked questions
How much is €5,000 gross net in Belgium in 2026?
€3,051.72 a month for a single white-collar employee with no children: €653.50 of social security, €1,245.27 of withholding tax and €49.51 of special social security contribution. With a partner who has no income and two children, it rises to €3,688.80.
What is the 13.07% deducted from my gross salary?
Your personal social security contribution, collected by the National Social Security Office (NSSO; ONSS in French, RSZ in Dutch). It funds pensions, health care and unemployment benefits. Below €3,403.62 gross a month, the work bonus reduces it.
Do expats pay less tax in Belgium?
Only under the special regime for inbound taxpayers and researchers. If you were recruited abroad or seconded within a group, did not live in Belgium or within 150 km of its border in the previous 60 months, and earn more than €70,000 gross a year, your employer can pay up to 35% of your gross pay as a tax-free allowance. It must apply within three months of your start date.
When do I become a Belgian tax resident?
When you establish your home in Belgium: where your family lives, or failing that, where you manage your affairs. Being registered in the National Register creates a legal presumption that you live in Belgium. From that date, your worldwide income is taxed in Belgium.
Why is my payslip different in May, June or December?
White-collar employees receive their double holiday pay (92% of a month’s gross pay), usually in May or June, taxed at a higher one-off rate: about 47.4% at €4,500 gross. Many sectors also pay a year-end bonus (13th month) in December, with its own withholding rate.
Do I need to file a tax return in my first year?
You file the year after you arrive, for the income earned since you settled. For 2025 income, the deadlines were 30 June 2026 on paper and 15 July 2026 online (MyMinfin), extended to 19 July 2026. The 2027 dates, for 2026 income, are not published yet: to be confirmed.
Is there a Belgium net salary calculator in English?
Yes: Indexo’s calculator works in English, computes every payslip line in your browser and sends nothing anywhere.
What next?
- Your net salary on arrivalWorked examples, first payslip, first tax return.
- The expat tax regimeA tax-free allowance of up to 35% of gross pay.
- First-year checklistEvery step, in order, with official links.
- Your payslip explainedEach line, with its Dutch and French label.
Sources
Parameters in force on 1 October 2026. Each parameter links to its source, the official one where it exists; a secondary source is flagged as such.
- Instructions administratives : les cotisations de sécurité sociale, National Social Security Office (NSSO).
- Instructions administratives : le bonus à l’emploi, National Social Security Office (NSSO).
- Calcul du précompte professionnel : annexe III de l’AR/CIR 92 et formule-clé 2026, FPS Finance.
- La cotisation spéciale pour la sécurité sociale, National Social Security Office (NSSO).
- Annexe III : précompte sur le pécule de vacances et les allocations exceptionnelles 2026, FPS Finance.
- Loi du 15 juillet 2026 portant réforme de l’impôt des personnes physiques, published on 29 July 2026, Belgian Official Gazette.
- Coming to Belgium: tax return, FPS Finance.
- Taxation of international executives: Belgium, KPMG, February 2024 (secondary source).
- Projet de loi portant des dispositions diverses, Belgian Chamber of Representatives, DOC 56 0963/001 of 3 July 2025 (explanatory memorandum: inbound taxpayers and researchers).
- Tax return 2026, FPS Finance.
- TOW : report du délai de rentrée de la déclaration en ligne au 19 juillet 2026 inclus, Forum for the Future, 13 July 2026 (secondary source).
- Posted workers, European Union (Your Europe), checked on 16 June 2026.