The A1 certificate confirms which country's social security legislation applies to a person. In one sentence: it proves that contributions for that person are paid at home, and not in the country where they happen to be working.
When you need it
In practice whenever somebody works in Germany while insured in their home country:
- an employee posted to a contract in Germany
- a sole trader travelling there to carry out the work themselves
- somebody who regularly works in several countries at once
It is not limited to long postings — it can be asked for on a one-day installation job.
What happens during an inspection
It is checked by customs enforcement (Finanzkontrolle Schwarzarbeit) directly on site. The worker has to be able to produce it on the spot — on paper or on a phone. "It is all sorted out back home" is not an answer that ends the inspection.
Without an A1, the person is treated as being subject to the German system, which means contributions payable in Germany plus a fine. The liability sits with the employer, not the worker.
Apply in advance, not afterwards
The application is made by the employer (or by the sole trader themselves) to the competent social security institution in the home country, before the work abroad begins. Retrospective issue is possible, but it is a complication — and once an inspection has already taken place, a certificate that turned up later no longer helps.
If you post people repeatedly, it is worth setting the process up so that an application goes out automatically with every new contract. We are happy to help with that.
