The A1 form is required for a worker to apply for temporary displacement to a member country of the European Union (except Denmark) or the European Economic Area (Switzerland, Iceland, Liechtenstein, and Norway).
This form is the same across Europe and is regulated through Rule 883/2004, relating to the coordination of social security systems.
Article 12.1 of this rule establishes that if a worker from a member state whose employer is permanently established in that state is sent to work temporarily in another member state, the worker will be subject to the legislation of the first member state as long as the planned duration of the work is no longer than 24 months and if said worker is not being sent as a replacement for another worker.
In other words, if someone is temporarily transferred to another member state of the EU, they could continue paying contributions to their country of origin while receiving social services in the country to which they were transferred through the European Health Insurance Card (EHIC).
How to apply for an A1?
In order for a worker to achieve a temporary transfer, it is necessary that the corresponding Provincial Directorate and Social Security Administration issue the form. For this to happen, the employer must request it at least four weeks before the worker departs.