Glossary
A1 Certificate
An A1 certificate is an EU/EEA/Swiss document proving you stay covered by your home country's social security while working temporarily in another member state, so you don't pay social contributions twice.
If you work across borders inside the EU, EEA, or Switzerland, the A1 certificate is the piece of paper that says which country’s social security system you belong to. Social security here means pensions, unemployment, sickness, and similar state contributions, not income tax. You can only be insured in one country at a time, and the A1 names that country.
It matters the moment you start working in a state that isn’t your usual one, whether you’re posted abroad by an employer, self-employed and taking a contract elsewhere, or regularly splitting work between two or more countries. Without it, the country you’re working in can claim you owe social contributions there, on top of what you already pay back home. The A1 is your proof that you’re covered elsewhere and shouldn’t be charged twice.
The catch most people miss is timing and who applies. Get the A1 before the cross-border work starts. Your employer usually requests it (or you do, if you’re self-employed) from your home country’s social security institution, never the destination. Inspectors in France, Germany, Austria, and Belgium really do check, and turning up without a valid one can mean fines or back-charges. How long a posting may last and how “multi-state” work gets assessed vary from case to case, so confirm the specifics for your situation.
Note that the A1 is purely about social security. It does not decide your tax residency or where you pay income tax, and it’s separate from your healthcare access abroad, which is covered by the EHIC / GHIC card. For moves between the EU and non-EU countries, an A1 doesn’t apply at all; instead you’d look at any totalization agreement between the two countries. Our relocation setup wizard can help you map which documents your move actually needs.
This is general information, not advice. Confirm the details with your national social security institution or a qualified professional before you rely on them.
Where you’ll meet this
- Your employer’s HR or payroll team asks for it before sending you on a posting or assignment in another EU country.
- A labour inspector or contractor on a worksite in France, Germany, or Belgium asks to see your A1 on the spot.
- You’re a freelancer invoicing clients in two countries and need to prove where your social contributions are paid.