Belgium: (Tele-)work Performed Simultaneously Within the European Economic Area – What Changes with the Moguntia Ruling?

European rules governing the determination of the applicable social security legislation for employees performing activities in several EU Member States can be complex. The Court of Justice of the European Union (CJEU) is regularly called upon to clarify the practical application of these rules. With its ruling in Moguntia / GKV‑Spitzenverband (C‑743/23), the Court confirms that all professional activities must be taken into account – including those carried out outside the European Union.

This decision is not limited to traditional cross-border situations: it also affects the application of the European Framework Agreement on Telework (2023), particularly the interpretation given by the Belgian National Social Security Office (NSSO). This article first recalls the general principles before examining the scope of the ruling and its practical consequences for Belgian employers. Read more here.