Judgment of the Court of Justice of the European Union of 11 December 2025: Simultaneous employment in several Member States and third countries: which activities should be considered when determining the 25% rule?

Article 13(1) of Regulation No 883/2004 determines how the applicable social security system should be determined when an employee works on a permanent basis in two or more Member States. In such cases, the social security legislation of the Member State of residence shall apply if the employee performs a substantial part (at least 25%) of his work in that Member State. If the employee does not perform a substantial part of his work in the Member State of residence, the legislation of the Member State in which the employer is situated shall apply. The Court of Justice of the European Union was asked for a preliminary ruling on whether the work performed by an employee in third countries should also be considered when assessing whether a substantial part of the work is performed in a Member State. The Court of Justice of the European Union answered this question in the affirmative.

1.    The facts

The employee in question lived in Germany from 1 December 2015 until 31 December 2020 and was employed by a company based in Switzerland. He worked on average 10,5 days per quarter in Germany, 10,5 days per quarter in Switzerland and the rest of the time in third countries.

On 19 November 2015, he contacted the GKV-Spitzenverband in Germany because he believed that he performed less than 25% of his work in Germany and was therefore not covered by the German social security system. However, the GKV-Spitzenverband took a different view, namely that he was covered by German social security legislation and therefore issued an A1 certificate to the employee concerned. The employee concerned lodged an objection to this decision.

The GKV-Spitzenverband rejected the employee's objection and confirmed the following:

- Pursuant to Article 13(1) of Regulation No 883/2004, a person who pursues professional activities in two or more Member States is subject to the legislation of the Member State in which he resides, if he performs a substantial part of his activities as an employed person in that Member State;

- In accordance with Article 14(8) of Regulation No 987/ 2009, a substantial part of the activities as an employed or self-employed person shall be considered to have been pursued in a Member State if, on the basis of an overall assessment of the situation of the person concerned, it is established that he performs at least 25% of his working time in the Member State where he resides and/or receives at least 25% of his remuneration there. The GKV Spitzenverband took the view that only work carried out in countries falling within the territorial scope of Regulations No 883/2004 and No 987/2009 was relevant for that purpose and therefore took into account only the working time spent by the employee concerned in Germany and Switzerland.

The GKV-Spitzenverband concluded from this that the employee concerned spent 50% of his working time in Germany, the Member State where he lives, which constitutes a substantial part of his employment.

The employee concerned appealed against this decision to the Sozialgericht (court of first instance in Germany, competent in social security matters). He argued that, to determine which social security legislation applied, not only the periods of employment he had completed in Germany and Switzerland should be considered, but also those in third countries, and that in any case he was already covered by the Swiss social security system during the period in question.

The Sozialgericht followed the employee's line of argument and ruled that he did not in fact perform a substantial part of his work in Germany, as he had only worked 10,5 working days per quarter (16% of his total working time) in Germany. Consequently, the Sozialgericht ruled that Swiss social security legislation applied, namely the legislation of the Member State where his employer was established.

The GKV-Spitzenverband then appealed to the Landessozialgericht für das Saarland, which referred the following questions to the Court of Justice of the European Union for a preliminary ruling: Must Article 13(1) of Regulation No 883/2004, read in conjunction with Article 14(8) of Regulation No 987/2009, be interpreted as meaning that, when assessing whether a substantial part of the work is carried out in a Member State, all of the employee's work must be taken into account, including his work in third countries, or only the employee's work carried out in European Member States?

2.    Decision

The Court of Justice has ruled that, when assessing whether an employee performs a “substantial part” of his work in the country of residence, all work performed in an employed capacity must be considered, including work performed in third countries.

This means that, in the context of the overall assessment required by Article 14(8) of Regulation No 987/2009, work in third countries must be considered in the same way as work in Member States. Based on this total working time – in all states where the employee is active, both Member States and third countries – it must then be determined whether at least 25% of that working time was performed in the country of residence.

Key message 

When an employee works in two or more Member States and a third country, Regulations No 883/2004 and No 987/2009 stipulate that all work performed worldwide must be considered when calculating the percentage of “substantial activities” in the country of residence.