Sick leave notification: How employers can defend against slackers

The sickness rate in Germany has recently decreased slightly. However, according to data from Techniker Krankenkasse, the total number of absences due to illness among employees remains high.

Between January and November 2025, German employees reported an average of around 18.6 days of illness. In the entire year of 2021, German employees were absent due to illness for around 13 days.

But how many of these are actually sick and how many are "playing truant" - i.e., only pretending to be sick?

No one knows exactly, but there are indications:

According to a survey by the opinion research institute Yougov from last year, more than every fourth person has already been absent from work with false claims.

A current study by the health insurance company Pronova BKK found that 60% of employees have already reported being sick, although they actually felt fit enough for work.

Seven percent do this "frequently".

For around half of those surveyed, this occurs "sometimes" or "rarely".

If an employee repeatedly reports being sick, although they are actually capable of working, the employer does not have to accept this.

Two specialist lawyers for labor law explain which legal options companies have to take action against such "truant illness".

Notification of illness:

These are the duties of employees

If an employee is sick, they must inform their employer immediately that they are unable to work and also how long their inability to work is likely to last.

"The employee can use the phone, email, SMS, WhatsApp or other messenger services for this," says Markus Bohnau, a specialist lawyer for labor law at the Kliemt firm.

A medical certificate of incapacity to work (AU) must currently only be submitted if it lasts longer than three days.

However, the Federal government plans to tighten this regulation so that a medical certificate of incapacity to work could be required from the first day.

However, this has not yet been legally resolved.

Nevertheless, the employer can already request an AU before the three days have passed, says Nathalie Oberthür, a Cologne-based lawyer.

Since 2023, this has been sent directly by the health insurance company to the employer as soon as the doctor has issued it.

If an employee is certified as sick, they must also behave in such a way that it does not impair their recovery, according to the expert.

What this means in practice varies from case to case.

According to IG Metall, if you have a broken arm, you can go to the cinema or a restaurant.

On the other hand, if you have influenza or a gastrointestinal infection, you should stay at home.

No AU available?

This is how the employer can react

If an employee is sick, they continue to receive their full salary from the company for six weeks.

However, if they cannot provide an AU and cannot prove their inability to work in any other way, the employer has the right to refuse payment, according to labor law expert Bohnau.

Some companies also pay the salary for longer.

In addition, a company can also impose sanctions if an employee cannot provide evidence of their inability to work with a medical certificate - for example, a warning or even termination.

Suspicious illness notification:

When can an employer question an AU?

"The employer can question a medical certificate if there are justified doubts about its correctness," says labor law expert Bohnau.

These are present in the following cases, among others:

The employee announced their inability to work in advance - for example, because their vacation request was rejected or there was a dispute with the boss.

The employee consistently has themselves certified sick shortly before or after vacation, weekends or public holidays.

The employer catches the employee behaving in a way that is detrimental to their recovery - for example, because they go to a party despite having influenza.

The employee resigns and has themselves certified sick for the rest of the contract term.

Suspicion of playing truant:

What can companies do?

If an employee plays truant, this can have far-reaching consequences and even lead to extraordinary termination, according to labor law expert Nathalie Oberthür.

However, the catch for companies is that it must be proven that an employee reported being unable to work, although they were not actually unable to work.

This is particularly difficult if a medical certificate is available.

The doctor who issued the AU will usually not admit to having made a mistake during the patient's examination.

One option is to involve the Medical Service of the statutory health insurance companies, which can check the correctness of the certificate and order an examination of the employee.

If the employee does not appear for this examination, this can help to undermine the probative value of the medical certificate, according to Oberthür.

However, the health insurance company can also reject the expert opinion if the cause of the AU is clearly evident from the medical records, says Oberthür.

This means that if the health insurance company concludes after reading the diagnosis by the doctor who issued the certificate that everything is in order, they do not have to create an expert opinion.

Medical service checks the accuracy of the AU

Another problem:

It can take several days or even weeks for an employee to be assessed by the Medical Service of the health insurance company.

Then it is often difficult to verify whether the employee was actually sick.

Another option is to look for evidence yourself.

In some cases, employers also consider hiring a detective agency to uncover a possibly feigned illness.

However, caution is required here, according to Bohnau.

On the one hand, this may violate the employee's right to privacy.

In addition, the Federal Data Protection Act and the Works Constitution Act must be observed.

A permissible measure could be, for example, to have the employee observed by a private detective during their leisure time.

However, this should be done taking into account the employee's personality rights.

If an employer takes action against an employee who has played truant, they must also consider the Works Constitution Act.

If there is a works council, it must be involved.

The works council has a right of co-determination in personnel matters, including the termination of employment contracts.

In individual cases, it may also be advisable to seek advice from a specialist lawyer for labor law.