Actual place of work determines applicable legislation, Supreme Court rules

The Supreme Court has clarified that the true location where an individual performs their work is the decisive factor in determining which country's legislation applies, particularly in cases involving employee delegation and social security certificates.

In a May 27, 2025 ruling (case file III USKP 137/24), the court stated that a higher court cannot limit its assessment of applicable legislation solely to the rules governing employee delegation. It must also investigate whether the employee genuinely worked in multiple member states.

The court stressed that the actual working conditions are paramount. It rejected the automatic application of findings from unrelated cases concerning different decisions by social security bodies. This ruling underscores the principle that factual circumstances of employment dictate legal jurisdiction.