The German “AU Certificate” – (un)shakeable evidential value

If an employee is unable to work through no fault of their own due to illness and is therefore unable to perform their work, the employee is entitled to continued payment of remuneration for a period of up to six weeks if the employment has existed for at least four weeks without interruption at the time of the illness, Sec. 3 (1) sentence 1, (3) German Continued Remuneration Act (Entgeltfortzahlungsgesetz - EFZG). The current political discussion in Germany about the large number of sick days and the potential risk of abuse, however, is missing a crucial aspect:

The employee must explain and prove their incapacity to work due to illness. The legally prescribed means of proof is the certificate of incapacity for work (Arbeitsunfähigkeitsbescheinigung - “AU Certificate”). The AU Certificate is a medical certificate confirming that the employee is unable to work due to illness. However, this does not mean that an employer must continue to pay remuneration upon presentation of any AU Certificate.

1. Principle: High evidential value of the AU Certificate

According to the case law of the German Federal Labour Court (Bundesarbeitsgericht - BAG), an AU Certificate has a high evidential value. If an AU Certificate is issued, there is prima facie evidence that the employee is unable to work due to illness. The employer is generally obliged to continue paying remuneration.

2. Undermining the evidential value

Simply disputing the illness or expressing general doubts is not sufficient to undermine the high evidential value of the AU Certificate. However, the evidential value of an AU Certificate can be undermined if there are specific factual circumstances that give rise to serious doubts about the incapacity to work due to illness. German Case law recognizes such circumstances in the following cases in particular:

• The AU Certificate is issued immediately after termination (regardless which party issued the notice of termination).
• The AU Certificate covers (largely) the entire notice period, i.e., the employee does not have to work until the termination date.
• During the certified period of incapacity to work due to illness, the employee performs other activities that are inconsistent with recovery.
• There is otherwise contradictory or suspicious behaviour on the part of the employee (e.g., announcement of incapacity to work due to illness, incapacity to work due to illness for the duration of a rejected vacation request, or similar). However, it is always necessary to evaluate all the circumstances of the individual case.
• The AU Certificate violates the Incapacity for Work Directive (Arbeitsunfähigkeits-Richtlinie) of the Joint Federal Committee (Gemeinsamer Bundesausschuss - G-BA). This Incapacity for Work Directive determines the procedure for determining and certifying incapacity for work due to illness for persons with statutory health insurance.

If the evidential value of an AU Certificate is undermined, the employer is entitled to withhold continued payment of remuneration. The employee then bears the full burden of proof that they were and/or still are unable to work due to illness. In order to meet this burden of proof, the employee will usually have to release the doctor who issued the AU Certificate from their duty of confidentiality. If the treating doctor is questioned as a witness in a lawsuit, it is important to dispel or confirm any existing doubts by questioning the doctor.

3. AU Certificates issued by telephone

According to the Incapacity for Work Directive, incapacity for work due to illness may only be determined based on a medical examination. The examination can be carried out in person or indirectly in person via video consultation. If it is not possible to determine incapacity for work due to illness during a video consultation, a telephone interview (medical assessment) can be conducted if there are no severe symptoms. In the case of a telephone medical assessment, the initial determination of incapacity for work due to illness should not exceed a period of five calendar days. If there was no patient-doctor relationship prior to the telephone medical assessment, the determination of incapacity for work due to illness should not exceed a period of three calendar days.

An AU Certificate issued properly by telephone has the same evidential value as an AU Certificate issued after a personal examination. The employer can only check whether an AU Certificate issued by telephone has been issued properly based on the circumstantial evidence:

• How far apart are the employee and the office of the issuing doctor?
• For what period was the AU Certificate issued?
• Has the employee been on sick leave based on an AU Certificate issued by the same doctor before?
• Is the employee repeatedly on sick leave, possibly based on AU Certificates issued by different doctors?

4. Online AU Certificate – rejection by the Hamm Regional Labour Court

Some employees even obtain online AU Certificates and submit these to their employer. Such AU Certificates are not based on direct, indirect, or telephone contact with a doctor. There are several websites that issue AU Certificates online, usually for a fee.

The Hamm Regional Labour Court (Landesarbeitsgericht Hamm - LAG Hamm) had to rule on an online AU Certificate in its judgment of 5 September 2025 – 14 SLa 145/25. The Hamm Regional Labour Court not only found that (i) the evidential value of an online AU Certificate is undermined, but also that (ii) the presentation of an online AU Certificate constitutes good cause within the meaning of Sec. 626 (1) German Civil Code (Bürgerliches Gesetzbuch - BGB) and can therefore justify extraordinary termination without notice.

In the underlying case, an employee received an online AU Certificate in exchange for a fee and presented it to their employer as proof of their incapacity to work due to illness. The employer recognized that the AU Certificate had been issued online and immediately issued an extraordinary termination without notice.

The employee filed an action for unfair dismissal against the termination. The Dortmund Labour Court (Arbeitsgericht Dortmund - ArbG Dortmund) initially upheld the action for unfair dismissal. Upon appeal by the employer, the Hamm Regional Labour Court overruled the decision of the Dortmund Labour Court and stated the following:

• If an AU Certificate is issued without a personal or indirectly personal examination or a telephone assessment by a doctor, the evidential value of this AU Certificate is already undermined by this procedural error. Contrary to the opinion of the Dortmund Labour Court, it is not the employer's responsibility to present additional circumstances that cast doubt on the employee's incapacity to work due to illness. Rather, the burden of proof lies with the employee to prove that they were unable to work. The Hamm Regional Labour Court also points out the following: In such cases, it must always be examined whether the circumstances that undermine the evidential value of the AU Certificate are to be regarded as so serious that they constitute strong evidence for the employer's claim that the AU Certificate was only feigned, so that the employee must additionally refute this evidence.
• If an employee submits such a (procedurally flawed) AU Certificate to the employer, the employee gives the false impression that it is a proper AU Certificate, i.e., a medical certificate issued based on a direct, indirect, or telephone medical assessment. This deception regarding medical contact as the basis for issuing the AU Certificate constitutes a significant breach of duty and, in itself, good cause within the meaning of Sec. 626 (1) BGB, which may justify extraordinary termination without notice.

These clarifications by the Hamm Regional Labour Court are to be welcomed: An online AU Certificate does not meet the requirements of the Incapacity for Work Directive and is therefore already undermined in its evidential value. An employer can therefore withhold continued payment of remuneration; the employee must prove that they were unable to work due to illness. Since the submission of an online AU Certificate also constitutes an attempt to deceive the employer in order to obtain continued payment of remuneration, the Hamm Regional Labour Court's statements on extraordinary termination without notice pursuant to Sec. 626 (1) BGB are also convincing.

5. Conclusion

The AU Certificate remains the central means of proof with a high, but not unshakeable, evidential value. If the evidential value of an AU Certificate is shaken, the employer is entitled to withhold continued payment of remuneration until the employee has proven their incapacity to work due to illness by other means. If the employee obtains an online AU Certificate and presents the employer with such, this may, according to the case law of the Hamm Regional Labour Court, even justify extraordinary termination without notice, depending on the overall circumstances of the individual case. As a result, employers are well advised not to continue paying remuneration without further ado, but to check every single AU Certificate for its evidential value.

Against this background, the current political discussion in Germany about the large number of sick days and the potential risk of abuse is missing a crucial aspect: employers have a tool at their disposal to defend themselves against unjustified claims for continued payment of remuneration. Every employer should know how to use this tool.