Key facts
- 2 working days to hand in the medical certificate, if required; since 1 January 2026, exemption twice per calendar year for the first day of incapacity, unless a company under 50 employees opts out.
- 30 days of guaranteed salary: 100% for white-collar employees hired for at least 3 months; for blue-collar workers, 100% for the first 7 days, then decreasing rates.
- 8 weeks: a relapse within this period does not open a new guaranteed salary, unless a certificate shows a different illness or accident.
- 6 months: deadline to request a return-to-work pathway (from 20 employees) and the incapacity period required before any medical force majeure procedure (previously 9 months).
- 30% of the health insurance benefits for the 2 months after day 30: contribution due since 1 January 2026 from employers with at least 50 employees, for sick employees aged 18 to 54.
How quickly must an employee hand in a medical certificate?
The employee must inform the employer of the incapacity immediately. If a collective labour agreement (CCT), the work rules (règlement de travail) or the employer requires it, the employee hands in a medical certificate within 2 working days from the start of the incapacity or from the request, unless a CCT or the work rules set another deadline, and except in cases of force majeure.
Certificate exemption: twice a year since 2026
Since 1 January 2026, the employee is exempt from providing a certificate twice per calendar year for the first day of an incapacity, whether it lasts one day or longer (three times from 28 November 2022 to 31 December 2025). The employee must still inform the employer immediately and give their address if they are not at their usual residence, but need not provide a certificate for that day at the employer's request. The exemption applies in all companies: only those employing fewer than 50 workers on 1 January may set it aside, through a CCT or an explicit amendment to the work rules.
An employee who does not comply with the obligations to notify, provide a certificate or accept a medical check is not entitled to guaranteed salary for the days before they comply.
Good to know: for every absence, record the date and time of notification, receipt of the certificate and use of the exemption. This is your evidence if you refuse guaranteed salary for days that are not covered.
How is guaranteed salary calculated for white-collar and blue-collar staff?
A white-collar employee hired for an indefinite period or for at least 3 months keeps 100% of their pay for the first 30 days, with no length-of-service condition. A blue-collar worker with 1 month of uninterrupted service receives 100% for the first 7 days, then a decreasing guaranteed salary up to day 30. The health insurance fund (mutualité) takes over from day 31.
| Period | White-collar, hired for 3 months or more | Blue-collar | White-collar, hired for less than 3 months |
|---|---|---|---|
| Days 1 to 7 | 100% | 100% | 100% |
| Days 8 to 14 | 100% | 85.88% | 86.93% |
| Days 15 to 30 | 100% | 25.88% below the health and disability insurance (AMI) ceiling and 85.88% above it, with the fund paying 60% of the capped salary | 26.93% below the AMI ceiling and 86.93% above it |
| From day 31 | Health insurance fund benefits | Health insurance fund benefits | Health insurance fund benefits |
For blue-collar workers, guaranteed salary is due from the first day (the waiting day was abolished on 1 January 2014), but only for their usual working days; the employer's top-up from day 15 to day 30 comes from CCT No. 12bis. A white-collar employee hired for less than 3 months follows the blue-collar scheme, with the same 1-month service condition, at their own rates (CCT No. 13bis).
Example: a white-collar employee on an open-ended contract is off sick for 45 days. The employer pays full salary for 30 days; from day 31, the health insurance fund pays a benefit of 60% of the capped gross salary.
Relapse within 8 weeks, adapted work, sickness during holidays: what must you pay?
Since 1 January 2026, a new incapacity starting within 8 weeks after the end of an incapacity that gave rise to guaranteed salary does not open a new guaranteed salary period (the period used to be 14 days): only the unused balance remains due. A new guaranteed salary is only due if a certificate shows a different illness or accident. Incapacities from 2025 count when applying this rule.
Example: a white-collar employee is off sick for 10 days in September 2026, returns to work, then falls ill again with the same condition 5 weeks later. They are only entitled to the remaining 20 days of guaranteed salary.
Throughout a period of adapted work authorised by the fund's medical adviser (médecin-conseil), a new incapacity gives no right to guaranteed salary (this exclusion lasted 20 weeks until 31 December 2025). The contract is not suspended during this adapted work.
Since 1 January 2024, an employee who falls ill during annual holidays keeps those holiday days. They inform the employer immediately, give their address if they are away from home and hand in a certificate in all cases, even if an exemption remains; they receive guaranteed salary for those days. If they want to take the recovered days straight away, they must ask no later than when handing in the certificate. Details on our page Annual leave in Belgium.
Medical inspector: what can you check?
You can have the employee examined by a medical inspector (médecin-contrôleur) of your choice and at your expense: the employee may refuse neither the visit nor the examination.
- A CCT or the work rules may set an availability window of no more than 4 consecutive hours, between 7 am and 8 pm, during which the employee remains available for the check.
- In the event of a medical disagreement, either party may appoint a medical arbitrator within 2 working days of the medical inspector's findings being handed over. The arbitrator decides within 3 working days, and the costs of the procedure are borne by the losing party (fees of €130.58 and administrative costs of €66.16 since 1 May 2026).
- An employee who evades the check is not entitled to guaranteed salary for the days before it.
On the health insurance side, the employee sends the incapacity certificate to the fund's medical adviser within 14 calendar days (blue-collar) or 28 calendar days (white-collar), failing which benefits are reduced; since 1 January 2026, the GP sends incapacities of more than 14 days and their extensions electronically. For its part, the employer sends the fund the data it needs through social risk declarations (DRS), such as the information sheet and then the return to work.
Finally, handle health data sparingly: keep only what is strictly necessary, restrict access to authorised people and set a retention period.
Return-to-work pathway in 2026: what to do at 8 weeks and at 6 months?
After 8 weeks of incapacity, the employer asks the occupational physician (conseiller en prévention-médecin du travail) to assess the employee's work capacity. If there is some, an employer with at least 20 employees must request a return-to-work pathway (trajet de réintégration) no later than 6 months after the incapacity began.
| When | Step |
|---|---|
| Throughout the absence | Apply the contact procedure set out in the work rules (who contacts the employee and how often); regularly inform all staff that they can ask for a pre-return visit |
| After 8 weeks | Have the work capacity assessed; if there is some, the employer may request a pre-return visit or a return-to-work pathway |
| No later than 6 months | Request the pathway if the company has at least 20 employees and the employee has some work capacity |
| During the pathway | Employee invited by registered letter (3 invitations at most), assessment within 49 calendar days, adapted work plan within 63 days (decision A) or 6 months (decision B); the employee has 14 days to accept or refuse the plan |
| After 6 months of uninterrupted incapacity | Medical force majeure procedure possible (previously 9 months), outside any ongoing pathway, by registered letter to the other party and to the occupational physician |
The contact procedure, mandatory in the work rules since 1 January 2026, is there to keep in touch, not to check whether the absence is justified. The employer may also ask the occupational physician to invite the employee to a pre-return visit, which the employee may refuse; travel costs are borne by the employer. The employee, for their part, must respond to invitations from the fund's medical adviser and the occupational physician, or risk losing or having their benefits reduced.
Failing to request the pathway in time is a level 2 offence, with a fine multiplied by the number of employees concerned (for offences since 1 September 2026: a criminal fine of €500 to €5,000 or an administrative fine of €250 to €2,500). Before any termination for medical force majeure, follow this procedure in full.
30% solidarity contribution: who pays for long-term sickness?
Since 1 January 2026, an employer with an average of at least 50 employees pays a solidarity contribution equal to 30% of the health insurance benefits due for the 2 months following day 30 of incapacity.
- Employees concerned: adults under 55 at the start of the incapacity, recognised as incapacitated for more than 30 days, for incapacities starting on or after 1 January 2026.
- Excluded, in particular: temporary agency workers, flexi-jobs, occasional workers in agriculture, horticulture, hospitality and funeral services, apprentices, and incapacities starting within the first 30 days of employment. Benefits paid during an authorised return to work do not count.
- Collection: the National Social Security Office (ONSS) calculates it and claims it by debit notice, with the contributions for the 3rd quarter after the incapacity began.
Example: if the health insurance fund pays €2,000 in benefits to a 40-year-old employee for the 2 months following day 30 of incapacity, their employer with 80 employees pays a €600 contribution.
This contribution follows on from the former “invalidity” accountability contribution, last calculated with the contributions for the 4th quarter of 2025 and repealed on 1 April 2026. A preliminary draft law, unanimously criticised by the National Labour Council (CNT, opinion No. 2.500 of 30 September 2026), would extend it to the next 2 months for incapacities starting on or after 1 January 2027: it is still only a draft.
Common mistakes
- Still applying “3 days without a certificate a year” or a “14-day relapse rule”: since 1 January 2026, it is twice a year and 8 weeks.
- Believing the certificate exemption only applies in large companies: it applies everywhere, unless a company with fewer than 50 employees has explicitly set it aside.
- Demanding a certificate for a first day covered by the exemption, or refusing a certificate because it arrives during the holidays.
- Using the contact procedure to check up on the absence or to question the employee about their illness.
- Paying guaranteed salary for a new incapacity that occurs during authorised adapted work: it is no longer due throughout that period.
- Forgetting the work capacity assessment at 8 weeks, then discovering the 6-month deadline too late.
Your checklist
- Update the work rules: certificate deadline, any opt-out from the exemption (fewer than 50 employees), availability window for checks, contact procedure.
- Record for each absence the date and time of notification, the certificate received and use of the exemption (2 per calendar year).
- Calculate guaranteed salary according to status and length of service, checking the 8-week relapse window.
- Send the days of guaranteed salary and its end date to the social secretariat, then complete the social risk declarations for the health insurance fund.
- Request the work capacity assessment after 8 weeks of incapacity.
- Request the return-to-work pathway no later than 6 months in if you have at least 20 employees.
- Regularly inform all staff that they can ask for a pre-return visit.
- Budget for the 30% solidarity contribution (from 50 employees), claimed with the contributions for the 3rd quarter after the incapacity began.
How Luxapps helps
FXP, for fiduciaries, and MySafeBox, for companies that run their own payroll, follow every sickness absence from certificate to payroll. In Belgium, they are configured to the country's rules, including guaranteed salary, and connected by API to your social secretariat (secrétariat social).
The employee uploads the certificate from the web or mobile portal; the document is stored encrypted with AES-256.
FXP and MySafeBoxIncapacity tracking, with its alerts, is configured to Belgian guaranteed salary rules, with an employer view and a fiduciary view.
FXP and MySafeBoxApproved absences, including sickness, feed the month's payroll variables without re-keying, then go by API to your social secretariat.
FXP and MySafeBoxGDPR built in (record of processing, data subject rights), AES-256 encryption, two-factor authentication, logging of every action and hosting in the EU by LuxOps, in Luxembourg.
FXP and MySafeBoxDocument templates and targeted distribution with acknowledgement of receipt: you keep a record of what each employee received.
FXP and MySafeBoxFrequently asked questions
2 working days from the start of the incapacity or from the employer's request, unless a collective agreement or the work rules set another deadline, and except in cases of force majeure. The certificate is only mandatory if a collective agreement, the work rules or the employer requires it, but the employee must always inform the employer immediately.
Since 1 January 2026, the employee may do without a certificate twice per calendar year, only for the first day of an incapacity; previously it was three times. Companies with fewer than 50 employees may set this exemption aside through a collective agreement or an explicit amendment to the work rules.
No if the new incapacity starts within 8 weeks after the end of an incapacity covered by guaranteed salary: only the unused balance remains due. A new guaranteed salary is due if the certificate shows a different illness or accident. This 8-week period has applied since 1 January 2026.
Yes for employers with 20 or more employees: if the occupational physician considers that the employee has some work capacity, the employer must request a pathway no later than 6 months after the incapacity began. The assessment of work capacity is requested after 8 weeks of incapacity. Failing to do so carries a level 2 fine per employee concerned.
Employers with an average of at least 50 employees, for employees aged 18 to 54 who have been incapacitated for more than 30 days, where the incapacity began on or after 1 January 2026. The contribution is 30% of the health insurance benefits for the 2 months following day 30. The National Social Security Office (ONSS) calculates it and claims it by debit notice.
Yes, since 1 January 2024. The employee must inform the employer immediately, give their address if away from home and hand in a medical certificate in all cases. The sick days are paid as guaranteed salary and the holiday days remain to be taken.
Official sources
- Employment Contracts Act of 3 July 1978, consolidated version (Justel)
- Act of 19 December 2025 on a strengthened return-to-work policy (Belgian Official Gazette of 30 December 2025)
- FPS Employment (SPF Emploi), sickness and accidents: suspension of the employment contract
- FPS Employment, overview of return-to-work pathways 2.0 and 3.0 (February 2026)
- FPS Employment, Code on Well-being at Work, Book I, Title 4 (health surveillance)
- ONSS, solidarity contribution for long-term sickness (instructions 2026/3)
- CNT, collective labour agreement No. 12bis (guaranteed monthly salary for blue-collar workers)
- INAMI (National Institute for Health and Disability Insurance), reporting incapacity for work
- CNT, opinion No. 2.500 of 30 September 2026 on the strengthened solidarity contribution
- FPS Employment, changes to the Social Criminal Code from 1 September 2026
This guide sets out the general rules in force on 5 October 2026. It is not legal advice for your situation (collective agreement, sector, employee status).