This is what the Court of Justice of the European Union ruled in its judgment of 14 May 2020 (case C-17/19). Other issues related to employing employees, for instance pertaining to labour law, are still outside its scope.

According to CJEU, A1 (E-101) certificates issued by a member state’s competent insurance institution are binding upon a competent institution and the courts of the host member state solely if they certify that a posted employee or an employee working in several EU member states is subject to the legislation of the first member state to obtain specific insurance benefits in matters relating to social insurance. 

These certificates are not binding with respect to the duties which the domestic legal regulations impose in areas other than ones related to social insurance. The duties related to an executed employment relationship may serve as an example, i.e. for instance the duties relating to the terms and conditions of employment or the terms and conditions of work.

It is worth noting that the Polish courts have taken a different opinion on this subject. In its judgment of 13 January 2015 (case II UK 205/13) the Supreme Court ruled that the A1 document has binding force also with respect to whether a given employee worked abroad under a posting or business travel. Posting and business travel alike are terms related in principle to labour law. Thereby, in the opinion of the Supreme Court, the A1 certificate also affects the other areas of employment that are unrelated to insurance.

More in the newsletter dedicated to HR law issues - PRO HR July 2020.