The Higher Labor Court of Thuringia decided that the processing of an employee’s private mobile phone number against his will is an extremely serious interference with the employee’s personal rights and was not justified in the specific case (decision on 16 May 2018 – docket number 6 Sa 442/17). Therefore, the warning issued in this context was ineffective.

The employee works for the district in the area of hygiene and infection protection. In the employee’s area of responsibility, hazards could arise which make it necessary to act outside working hours. Until the end of 2016, this was ensured and organized by on-call duty. Pre-defined employees were assigned to on-call duty 24 hours a day, seven days a week. A business mobile phone was made available for the necessary contact. In addition, the employees received additional remuneration for on-call duty.

With the purpose of saving costs, the employer decided to reorganize the coverage of necessary activities outside working hours. From January 2017, on-call duty was limited to weekends and public holidays. Outside these times in the event of an emergency, the control centre should try to contact one of the seven employees in the area of hygiene and infection protection by any means. It was left to chance which employee was contacted. For the implementation of this concept, the employer requested notification of the employee’s mobile phone number.

The employee refused to give his mobile phone number and therefore received the warning.

With reference to the national data protection law, the court decided that the refusal of the employee was not a breach of duty. The mobile phone number was not necessary for the performance of the employment relationship or for the purpose of personnel deployment. The processing of such data is only permissible in exceptional cases if the employer, is unable to perform a legitimate task for which the employee is employed, or is unable to perform it in full or in a lawful manner, without knowledge of the mobile phone number. Additionally, it must be impossible or unreasonable to organize the performance of the task by other means.

The employer’s interests in determining work processes and work organisation within the framework of his entrepreneurial freedom did not prevail over the employee’s right of personality and did not comply with the principle of proportionality. The interference in the personal right of the employee is the collecting of the mobile number and thus the possibility of contacting the employee at any time and in any place. The employer wants to have the mobile number only and exclusively to contact the employee in his spare time.

Within a detailed weighing of interests, the court decided, that it is particularly important to consider that the employer has intentionally chosen to change his organisation of processes. The employer no longer wants to decide beforehand who he wants to use for work performance, but leaves this to chance with the result of interference in the employees’ leisure time. In addition to that, the court held that the employer wanted the personal mobile number to cover basic tasks and not just emergencies.

The decision makes clear that employers are not allowed to contact employees arbitrarily during their free time. Even if the court refers here to the data protection law, it is also unlawful under German labour law to make use of the employee outside working hours and to demand from him a permanent readiness. However, the fact that the decision is based on data protection law emphasizes its important role in employment related matters. Employers should carefully proof whether it is necessary to ask the employee to give the private mobile phone number or if there are alternative means to perform the task in question. If employees voluntarily provide their private mobile number to the employer, the use of it shall be in line with the purpose for which the private mobile phone number was provided.