Are sick days deducted from annual leave? What if you fall ill during annual leave?

Is a medical report a type of leave?

The Labour Law does not provide paid "sick leave". When an employee cannot work because of illness or an accident, the employment contract is suspended for a period of incapacity. The law states explicitly that no wages accrue for periods in which the employee cannot work because the contract is suspended (Labour Law No. 4857, Art. 25/I).

The employee's loss of income is covered by the temporary incapacity benefit paid by the Social Security Institution (SGK):

The basis is Art. 18 of Law No. 5510. For monthly paid employees, the benefit paid by the SGK is offset against the wage paid by the employer (Labour Law, Art. 48). A collective agreement or employment contract may provide more favourable terms, such as the employer paying the first two days.

Are sick days deducted from annual leave?

No. Under Art. 56/4 of the Labour Law, other leave granted by the employer, rest and sick leave cannot be offset against annual leave. The Ministry of Labour and Social Security also states that periods of medical rest cannot be deducted from annual leave, and decisions of the 9th Civil Chamber of the Court of Cassation take the same view (E.2016/23909, K.2020/8593).

So a practice of "you took a lot of sick days, we are deducting them from your annual leave" is unlawful. Medical reports do not touch the balance.

Do sick days affect annual leave entitlement?

One year of service is needed to earn annual leave. The law counts sick days within that year as time worked, but with a limit: under Art. 55/a, days beyond the period set in Art. 25/I-b are not counted. That period is the notice period in Art. 17, based on the employee's seniority, plus 6 weeks:

Days beyond the limit are not counted as time worked; under Art. 54/2 the entitlement date moves back by that many days. For example, for an employee with 4 years of service who is on continuous medical rest for 130 days, 98 days count as time worked; the remaining 32 days push the next entitlement date back by 32 days. We explain how the entitlement date is calculated in our annual leave calculation guide; you can also see the shift with the free annual leave calculator.

The same period is also the threshold for the employer's right to terminate without notice: if the illness lasts longer, the employer may terminate the contract without notice (Art. 25/I-b). This is a right, not an obligation; severance pay is due on termination.

What if you fall ill during annual leave?

Neither the Labour Law nor the Annual Paid Leave Regulation addresses illness during annual leave, and no binding Court of Cassation decision or Ministry opinion on the point could be found.

The prevailing view in legal doctrine is that sick days and annual leave days should not overlap, because annual leave is meant for rest and Art. 56/4 prohibits offsetting: days spent ill cannot count as rest. The recommended practice is:

1. The employee notifies the employer of the report without delay and gives the report dates.
2. Annual leave days that overlap with the report are not treated as used and are credited back to the balance.
3. The leave does not extend automatically; the employee replans the remaining days with the employer. To extend the return date, the employee makes a new leave request.

This approach favours the employee and leaves a clear record for the employer, who bears the burden of proving that leave was granted.

Medical reports and personal data

Health data is special category personal data (KVKK, Art. 6). The employer should take only what it needs from a report: the start and end dates, the type of report and its source. The diagnosis should not be requested, and report documents should be stored separately with restricted access. On the team calendar, an employee on medical rest should appear as "on leave", without showing colleagues the leave type or reason. See our guide to KVKK and employee data for details.

How İzin360 handles it

• A medical report can be recorded over annual leave. When the report is approved, the overlapping annual leave days are credited back to the balance automatically and appear in the transaction history with the reason.
• The entitlement date shifts automatically. Sick days beyond the notice period plus 6 weeks are calculated from the employee's seniority and push the next entitlement date back.
• Medical reports do not reduce the balance; they appear in the payroll export with the suggested SGK missing-day reason "01 – Medical rest".
• Health information stays private. On the team calendar, an employee on medical rest appears only as "On leave"; report documents are stored encrypted and only authorised people can see them.