Illness During Annual Leave in Luxembourg

1. The non-deduction principle

Article L.233-11 of the Labour Code provides that if an employee falls ill during recreational leave in such a way as to be unable to enjoy it, the sick days recognised as such by a medical certificate are not counted as leave days. They may therefore not be charged against the statutory leave entitlement.

In practice, two separate regimes coexist during the same calendar period:

• annual leave days, deducted from the employee's statutory balance;
• sick days, covered under incapacity for work and not charged to leave.

The switch from one regime to the other is triggered by the onset of illness, provided the medical certificate is submitted on time (see section 2).

2. Employee's obligations: the medical certificate

The non-deduction benefit is strictly conditional on submitting a medical certificate. The Labour Code distinguishes two situations based on the employee's location:

Employee in Luxembourg

The medical certificate must be sent to the employer within three working days of the onset of illness (Art. L.233-11). This deadline runs from the first day of incapacity, even if that day falls on a weekend or public holiday (the deadline is counted in working days, not calendar days).

Employee abroad

When the employee is on leave abroad, the law sets no specific time limit: the employer must be notified as quickly as possible. In practice, sending the certificate by registered post or digitally (email, internal HR app) as soon as it is issued by the doctor is strongly recommended to avoid any dispute.

3. Rescheduling the remaining leave

Leave is not lost

Once the period of incapacity ends, the unconsumed leave days do not disappear. The employee retains in full the right to the credited-back days. The new leave dates are agreed by mutual consent between employer and employee (Art. L.233-11), following the same rules as for the initial scheduling.

The employer cannot unilaterally impose new dates, nor can the employee fix them alone without the employer's agreement. In the event of a dispute about rescheduling, the ITM may be consulted.

Worked example

4. Extension to the leave-savings account (CET)

The leave-savings account (compte épargne-temps, CET) is an optional arrangement allowing employees to bank leave or rest days for deferred use. When an employee draws on CET days and falls ill during that period, the same non-deduction logic applies: certified sick days are not deducted from the CET and the corresponding days are credited back.

This principle is consistent with the general rule of article L.233-11: whatever the type of leave taken (ordinary statutory leave or CET days), illness cannot consume those entitlements in place of actual rest.

5. Illness and leave accrual

Beyond the deduction question, article L.233-6 provides an important clarification about the effect of illness on leave entitlement itself: absences due to illness or accident are treated as days of actual work for the purpose of calculating annual leave entitlement.

The direct consequence: an employee on sick leave continues to accrue leave entitlement during the period of absence. The employer may not refuse to grant leave by citing those absences as non-worked periods that reduce the entitlement.