Summary

A national rule which requires an official of the EU who pursues an ancillary occupational activity of teaching in the territory of that Member State to be subject to the social security schema of that Member State is precluded by EU-law. 

Question

Must Article 14 of Protocol (No 7) on the privileges and immunities of the EU, the principle of a single social security schema applicable as referred to in Regulation No 883/2004 and the principle of sincere cooperation as enshrined in Article 4(3) TEU be interpreted as precluding legislation of a Member State which requires an EU official who pursues an ancillary occupational activity of teaching in the territory of that Member State to be subject to the social security scheme of that Member State?

Ruling 

Article 14 of Protocol (No 7) on the privileges and immunities of the EU, the principle of a single social security schema applicable as referred to in Regulation No 883/2004 and the principle of sincere cooperation as enshrined in Article 4(3) TEU must be interpreted as precluding legislation of a Member State which requires an official of the European Union who pursues an ancillary occupational activity of teaching in the territory of that Member State to be subject to the social security scheme of that Member State.