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REQUIRED All of Belgium

I am ill and cannot go to work. When must I tell my employer, and do I need a doctor's certificate?

In short

Yes. You must tell your employer straight away. If a certificate is requested, you usually have to hand it in within 2 working days. Twice a year, you may not need a certificate for the first day of illness.

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This rule in 52 seconds
Video transcript

You wake up with a fever and cannot go to work. Required: Tell your employer straight away. If a certificate is asked for, it is usually due within 2 working days. The right way: Phone first, then hand in the certificate on time. Twice a year, the first day may not need one. If you are late: For some days: Pay may be withheld; Late to the fund: Benefit cut by 10 %; Fake certificate: A separate crime.

What is not allowed, what is required?

  • Tell your employer straight away that you are ill. This is always compulsory, except in case of force majeure (overmacht / force majeure).
  • If the collective agreement, the work rules or the employer requires it, you hand in a doctor's certificate (geneeskundig getuigschrift / certificat médical). If no other deadline is written down, the deadline is 2 working days.
  • Since 1 January 2026, you can be exempt from a certificate for the first day of illness twice a year (previously three times). Employers with fewer than 50 employees can remove this exemption through a collective agreement or the work rules.
  • Your employer can send a control doctor (controlearts / médecin contrôleur). You must cooperate with the check. Your certificate states whether you are allowed to leave home for it.
  • For the first 30 days you receive guaranteed pay (gewaarborgd loon / salaire garanti); for blue-collar workers, the health insurance fund also pays for days 15–30. After that, your health insurance fund (ziekenfonds / mutualité) pays. You must notify the fund within 14 days as a blue-collar worker, 28 days as a white-collar employee and 7 days if you are unemployed.

Penalty and indirect consequences

PENALTY NOTICE
Fine / payment
Not a fine, but loss of pay: if you avoid the check without a good reason, you may not get guaranteed pay for the days before the check. If you inform your employer late or hand in the certificate late, you may not get guaranteed pay for some days. If you notify the health insurance fund late, your benefit is reduced by 10% for the period of the delay.

Legal basis:Arbeidsovereenkomstenwet, art. 31 §3/1 (Justel)FOD WASO – Schorsing: ziekte en ongeval

Court / prison
No prison sentence (a false or bought certificate is a separate offence).

Legal basis:Strafwetboek Boek II, art. 451 (Kamer DOC 55 3518/011)

What really matters: the indirect consequences

Why does this rule exist?

Your employer needs to know straight away so that they can reorganise the work. The certificate and the control doctor prevent abuse while protecting people who are genuinely ill. Guaranteed pay means that someone who is ill does not lose all their income in the first weeks.

Where can you go?

  • Accountant or social secretariatDimona, e-invoicing and tax obligations
  • Organisations for self-employed peopleFlanders: Unizo · Wallonia and Brussels: UCM
  • Tax office (FOD Financiën / SPF Finances)Declaring foreign property and accounts
  • Social interpreterAt the municipality, the OCMW/CPAS, school and hospital, you can ask for an interpreter in your language; it is often free.

This site does not handle individual cases; it points you to the right service. All help addresses

Source and reliability

Official source
Source check
15 / 15 statements in an official source
Checked: 02.11.2026
Last checked
22.10.2026
Rules can change
Show the 15 checked statementsopen

The checked statements are in Turkish, as in the source text. This check does not replace legal advice.

General information, not legal advice. For your own situation, ask a lawyer or free legal aid. How was this information prepared?

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