view all news & events


Always ready – The employer and the private mobile number

In employment law, issues relating to permanent accessibility of employees via business smartphones are all the rage right now. They are discussed over and over, even if, from the employers’ point of view, there is often little room for discussion based on the current legal situation. What is less a topic of discussion is whether employees without a business smartphone need to provide their private mobile number to their employer so that they may be reached at least in emergencies. The 6th Senate of Thuringia State Labor Court has recently taken a position on this issue. When initiating an employment relationship, prevailing opinion holds that employers are generally deemed to have legitimate interests to collect, store, and use at least one additional option to rapidly contact employees, in addition to a postal address. The private landline number is used for this purpose on a regular basis. It is disputed whether a private mobile number or a private email address may also be stored without express consent. In view of technical developments and the customary nature of these communication channels, we believe this to be the case, however. This is necessary to establish an employment relationship. The entry into force of the General Data Protection Regulation and the new Section 26 Federal Data Protection Act from May 25, 2018 will not change this initial situation.

In two cases, the 6th Senate of Thuringia State Labor Court recently decided on the admissibility of the requirement to provide private mobile numbers in existing employment relationships (May 16, 2018 – 6 Sa 442/17; 6 Sa 444/17). The defendant employer, a local health authority, had requested private mobile numbers from employees to be able to reach them in an emergency even outside of on-call duty. Two employees failed to comply with this instruction and received a warning. Both court cases dealt with the removal of these warnings from the personnel file.

According to the 6th Senate, it could ultimately remain open whether there would even be a basis for claims to provide private cellphone numbers. In any case, a claim is limited by the Thuringian State Data Protection Act. Having to provide private mobile numbers constitutes a considerable encroachment on the right to informational self-determination, which must be justified by legitimate interests of the employer. The relevant assessment procedure must show that the intervention is appropriate. According to the court, it must be borne in mind that an obligation to disclose a private mobile number interferes particularly deeply with employees’ personal spheres. Due to constant accessibility, employees can no longer avoid the employer without pressure to justify themselves and thus cannot properly rest. This is independent of the probability of actually being contacted and consulted in an emergency. The employer itself had caused the problem by changing the existing system of on-call duty and also had other possibilities to protect against emergencies.

Practical tip

The two judgments of Thuringia State Labor Court, which are only available as press releases to date, are likely strongly tailored to the circumstances of the specifically decided facts. The assessment is also to be carried out beyond the Thuringian Data Protection Act, however, within the scope of the Federal Data Protection Act. Accordingly, a general exclusion of requesting private mobile phone numbers by employers and their data processing certainly does not exist. It must be reviewed in each individual case whether the request for private mobile numbers is actually necessary to perform the employment relationship, where a blanket request for mobile phone numbers will probably not be necessary. In case of doubt, employers that want to safely comply with data protection law will obtain employees’ consent to process private mobile numbers. The decisions urge employers to be cautious. The widespread and apparently normal request and processing of private mobile phone numbers is by no means always harmless under data protection law and a “matter of course.” In view of the General Data Protection Regulation in force since May 25, 2018, unlawful data processing in this respect could result in severe fines. The two decisions show once again how much data protection law has now arrived in the “traditional” practice of employment law and HR practice.


Martin Greßlin

Dr. Martin Greßlin


visit profile