Student work: three counters, and only one of them ruins you
Everyone knows about the 650 hours. Almost nobody knows they only do one thing: set your contribution rate. Remaining a dependent child of your parents depends on a completely different ceiling, expressed in euros. And keeping your child benefits depends on a third counter, which differs by Region. Three counters, three logics — and mixing them up is exactly how you lose money.
Student work in Belgium rests on three systems that do not talk to each other: social security counts hours, the tax office counts euros, and child benefits count yet other hours, with rules that differ by Region. Staying under 650 hours therefore guarantees nothing at all on the other two fronts.
The 650 hours: what they do, and what they do not do
The quota went from 475 to 650 hours on 1 January 2025. It is not a cap on work: beyond it you can carry on, simply at ordinary contributions. Plenty of students stop at 650 hours believing it is forbidden — it is only less advantageous.
It goes back to 650 on 1 January. Unused hours are lost, and hours worked over in one year do not reduce the next year's quota. You can check your balance on studentatwork.be or in the Student at work app, and your employer can check it before hiring you.
Two schemes combine with the quota. Voluntary association work: 190 hours a year on top, beyond which the hours come off your 650. And casual work in the hospitality sector, with its own 50-day system, also combinable.
What you actually pay
| Situation | Student share | Employer share |
|---|---|---|
| Within the 650 hours | 2.71% | 5.42% |
| Beyond 650 hours | 13.07% | ordinary employer contributions |
The gap is more than ten points on your gross. On an hourly wage of €14, it comes to about €1.45 an hour — roughly one hour of work lost for every ten hours worked outside the quota.
A Dimona declaration of type “STU” is mandatory as soon as the solidarity contribution applies. That is not your job, it is the employer's — but its absence is exactly what tips you out of the favourable scheme, without you seeing it.
Remaining a dependent child of your parents: a ceiling in euros
This is the second counter, and it has nothing to do with hours. For 2025 income, a child remains a dependant if their net resources do not exceed €12,000.
The old table distinguished the case of a couple, a parent taxed separately and a single parent of a disabled child, with three amounts between €4,000 and €7,300. It is gone. One figure applies today, whatever the parents' situation. If you come across a table with three amounts, it is out of date.
The important word is “net”. The official calculation is far more favourable than it looks:
A gross salary of €8,000 after contributions. Take off the allowance of €6,840, and €1,160 is left. The flat-rate expense of 20% gives €232, below the minimum of €570: so €570 is used. Net resources: €590. That is a long way from €12,000 — the child comfortably remains a dependant.
student@work publishes two gross benchmarks for 2026, valid only if you have no other resources and do not claim actual expenses: €22,385 is the amount above which you are no longer a dependant, and €15,971.43 the amount below which you pay no tax yourself.
Child benefits: one counter per Region
Before 18, no limit: the entitlement is kept whatever the number of hours worked. From 18, each Region applies its own rule.
per quarter
+ 240 h/quarter
+ 80 h/month
In all three Regions, compulsory internships required for your diploma and dual learning are not counted. The competent bodies are FAMIWAL and AVIQ in Wallonia, Famiris and Iriscare in Brussels, and Groeipakket in Flanders — they are the ones who decide in case of doubt.
The contract, and what it gives you
The student employment contract is written and mandatory. It is fixed-term, drawn up in two copies, concluded individually, and signed no later than the moment you start work. The employer sends a copy to the Social Legislation Inspectorate within seven days and declares the job in Dimona.
Your tax return
It is mandatory from 18, even if your income is well below the taxable threshold. Minors only have to file if they have certain income, professional or miscellaneous.
No professional withholding tax is deducted if three conditions are met: a written student employment contract, work that does not exceed 650 hours over the year, and no ordinary social security contributions due. If withholding tax was deducted anyway — which happens when the quota runs out during the year — the return is precisely what lets you get it back. Not filing it means leaving that money with the Treasury.
Classic pitfalls
⚠️ Believing that 650 hours protects everything. They only concern the contribution. You can stay under 650 hours and still go over the tax ceiling if your hourly wage is high, or lose child benefits in Brussels by packing your hours into a single quarter.
⚠️ Packing your hours into the wrong moment. In Brussels, the limit is quarterly. Working 300 hours in one quarter and then nothing at all costs you that quarter's benefits, whereas the same volume spread out would cause no problem.
⚠️ Mixing up a student job and self-employed status. These are two entirely separate schemes. If you invoice for your work rather than receive a salary, it is the student self-employed status that applies, with its own contributions and its own thresholds.