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In today's increasingly interconnected global labour market, it is common practice for companies based in Switzerland to send employees abroad for business purposes – whether for a short client meeting, a project lasting several weeks, or a longterm assignment. However, employers deploying staff within the EU member states and Switzerland or the EEA member states and Switzerland must comply with important social security regulations – not only concerning social security protection but also regarding applicable social insurance jurisdiction. A key document in this context is the so-called A1 certificate.
This article explains the necessity of the A1 certificate for assignments from Switzerland to an EU or EEA member state, its legal basis, and the possible consequences of failing to present such proof.
What is an A1 Certificate?
The A1 certificate is an official form confirming that an employee, during a temporary work assignment in another country within the European Economic Area (EEA), the EU or Switzerland, remains subject to Swiss social security legislation. It is issued by the competent Swiss AHV compensation office via the ALPS platform. This document is required for both short business trips and longer secondments and serves as proof to authorities in the host country.
Who Needs an A1 Certificate?
The A1 certificate does not apply to all Swiss employees posted to an EU or EEA member state. It can only be requested in the following cases:
- Swiss or EU nationals on assignments from Switzerland to an EU member state
- Swiss or EEA nationals on assignments from Switzerland to an EFTA member state
If a non-EU national is posted from Switzerland to an EU member state, it must be verified whether a bilateral social security agreement exists. If so, the employee may remain subject to Swiss social security during the assignment. In such cases, a Certificate of Coverage (CoC) must be obtained instead.
For How Long?
As a rule, the A1 certificate can be issued for a period of up to two years. Under an exceptional agreement, it can be extended up to five years for assignments from Switzerland to an EU or EEA member state. However, when the A1 certificate is issued for an employee who is employed in one EU member state and posted to another EU member state, the maximum period remains two years. The five-year possibility applies only to postings from or to Switzerland. This is because the Agreement on the Free Movement of Persons between Switzerland and the EU, as well as the EEA Convention, do not apply to all nationals equally.
In the context of multi-state employment, the A1 certificate can generally be issued without a time limit.
Legal Basis
The issuance and use of the A1 certificate is based on the Agreement on the Free Movement of Persons between Switzerland and the EU, as well as Regulation (EC) No 883/2004 on the coordination of social security systems for relations between Switzerland and an EU member state. For relations between Switzerland and an EEA member state, the EFTA Convention applies.
In principle, the territoriality principle applies within the EU, Switzerland, and EEA, meaning social insurance is required in the country where the work is performed. However, exceptions exist – such as in the case of secondments or multi-state employment.
The aim of these rules is to ensure that employees are not simultaneously subject to social security contributions in two countries, or not covered at all. The A1 certificate helps guarantee that an employee remains subject to Swiss social insurance during a temporary assignment abroad.
Necessity for Assignments from Switzerland
The A1 certificate is mandatory for every professional stay within the EU / EEA area and in Switzerland – regardless of the duration of the assignment. This means:
- Even a one-day client visit in the EU or EFTA abroad requires an A1 certificate.
- It is equally mandatory for multi-month secondments or assembly assignments.
The A1 certificate serves not only as proof of social insurance coverage in Switzerland but also protects the employee in case of illness or accident, and exempts the employer from making contributions in the host country. In Switzerland, too, the A1 certificate is required and often checked during labour market inspections. If it is not available at the time of an inspection, the employee is generally required to cease work immediately and may only resume once the certificate has been obtained.
Example
Yves Scharner is employed by TB Security AG in Zurich. He also resides in Zurich and is a Swiss national. On Monday, 15 September 2025, he is scheduled to travel to Paris (France) for a one-day business trip. The purpose of the trip is an important business meeting with a French partner company. Yves will give a presentation on a new product at the partner's office and negotiate a potential future collaboration. A lunch break at a nearby restaurant is planned to reflect on the discussions. In the afternoon, he is to meet another client in Paris to discuss further details and coordinate next steps. He will return to Zurich in the evening.
Even though the assignment only lasts one day, an A1 certificate must still be obtained. In addition, it must be checked whether a SIPSI notification (in accordance with the Posted Worker Directive) is required for regulatory purposes.
Consequences of Not Having an A1 Certificate
Failing to present a valid A1 certificate can have serious consequences for both employees and employers:
- Fines and penalties: In countries such as Germany, France or Austria, significant fines may be imposed if a valid A1 certificate cannot be presented during inspections.
- Work bans: The employee may not be allowed to carry out their professional activities abroad without the appropriate certificate.
- Double insurance contributions: Without an A1 certificate, the employee may be required to pay social security contributions in the host country as well.
- Reputation damage and delays: Companies risk reputational damage with international partners and project delays.
Conclusion
The A1 certificate is essential for assignments from Switzerland to the EU or EEA area. It ensures that the employee remains subject to Swiss social security legislation while working abroad and protects both parties from unnecessary costs, legal uncertainty, and sanctions. Given the clear legal obligation, every secondment – even a short business trip – should be carefully planned and the required form requested well in advance. This is the only way to avoid legal and financial risks and ensure a smooth international work assignment.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
