While everyone in Belgium has the right to reclaim holiday days if they fall ill while on leave, new research shows that most employees are not aware of their rights.
Just 26% of Belgian employees who fell ill while on holiday last year got these days back from their employer, according to a survey released this week by HR group Attentia.
Since 2024, employees have been legally entitled to claim back leave days on which they fall ill. For those who faced this situation in 2025, 74% say they lost these days, with the median number of days lost being four, according to the survey of Belgian employees conducted in April.
"Half simply did not ask their line manager to take the sick days at a later date," said Nathalie Lucas, a senior legal consultant at Attentia. These employees simply lost the days as a result. The reasons for the lost days vary.
Of those who did request the days back from their employer, a quarter were refused.
"This may be due to a failure to comply with the conditions: for instance, the employee must notify the employer immediately and submit the certificate within two working days. Additionally, it is possible that not all employers are equally well informed about the regulations," Lucas added.
Awareness of holiday rights remains low
Attentia's survey shows that one in four employees do not know about the rules, with younger people and those working in smaller businesses being more likely to be less aware of these holiday rights.
For employees under 35, 31% were unaware of the holiday rights. This compares to 23% for those aged 35 to 54, and 20% for those aged over 55.
Knowledge also scales with the number of employees a company has: only 20% of employees in companies with more than 250 employees were not aware of the holiday rights, but this rises to one in three for those working in companies with less than 50 employees.
"That is understandable," said Lucas. "Smaller companies often have less specialised HR capacity to quickly put new regulations into practice."
Bert Engelaar, president at trade union ABVV-FGTB told The Brussels Times that the legislation is still relatively new and unknown by employers and employees and this may explain the results.
"There is therefore still work to be done, certainly for companies’ HR departments – as not all employers are aware of it – but also for us as a trade union, because people need to know their rights and be able to exercise them. Too many employees are still unaware that it is possible to make up for their holiday days," he said.
Still, awareness of the right and having HR policies in place is only part of the story. "Of course, it also requires a degree of assertiveness, and the procedure is strict," said Engelaar. "As an employee, you must notify your employer immediately, provide a medical certificate within two working days, and explicitly request to make up the days."
Additionally, this arrangement only applies to employees' statutory (legal) leave and not to any other form of leave, such as seniority days or leave due to reduced working hours.
"If you meet these conditions, your employer must, of course, comply with the law," noted Engelaar. He explained that employees could call on legal support either from their trade union, or through the labour inspectorate.
"Holiday is holiday and sickness is sickness; everyone must retain the right to four weeks holiday per year."
