A1 certificate for Switzerland: what employers need to know

A practical employer guide to A1 certificates, Swiss social security coordination, secondments, posted workers, cross-border work, and the immigration steps that still need to be checked.

Short answer

An A1 certificate shows which country's social security system applies when an employee works temporarily across borders. For Switzerland, it is most relevant for secondments, posted workers, cross-border workers, multi-state work, foreign payroll arrangements, and remote-work patterns involving Switzerland. It is not a Swiss work permit. It does not replace Swiss notification, posted-worker, payroll, tax, or work authorization checks.

💡 Check the Swiss hire feasibility. Permitree gives employers the likely Swiss route, timeline, document checklist, costs, risks, and process overview before they move into the full hiring or mobility case.

Quick snapshot

What an A1 certificate does

An A1 certificate confirms that an employee remains subject to one country's social security legislation while temporarily working in another country. In practice, it helps employers show where social security contributions should be paid.

For Switzerland, A1 certificates are most often used in EU/EFTA social security coordination. They can also matter in Swiss outbound assignments, inbound assignments to Switzerland, and work patterns where the employee works in more than one country.

Legal basis: Swiss-EU Agreement on the Free Movement of Persons, Annex II; Regulation (EC) No 883/2004; Regulation (EC) No 987/2009.

What an A1 certificate does not do

An A1 certificate does not give the employee permission to work in Switzerland. It also does not decide whether the person can enter Switzerland, live in Switzerland, or perform the planned work activity.

A valid A1 may help avoid duplicate social security contributions, but the employer may still need a Swiss work permit, online notification, posted-worker filing, salary check, payroll review, tax withholding analysis, or permanent establishment review.

Simple rule: A1 answers the social security question. It does not answer the immigration question.

Legal basis: FNIA/AIG Art. 11, 18, 22, 117 and 117a; VZAE/ASEO Art. 14; VFP Art. 9.

When employers should check A1 for Switzerland

Secondments to Switzerland

If a foreign employer sends an employee temporarily to Switzerland, check A1 before the assignment starts. If the posting conditions are met, the employee may remain covered by the sending country's social security system, often for up to 24 months under EU/EFTA coordination rules.

Posted workers in Switzerland

Posted-worker cases can involve several Swiss compliance steps at once: work authorization or notification, salary and working-condition checks, expense rules, document availability, and social security evidence. A1 may be part of the file, but it is not the filing that authorizes work.

Cross-border workers

A cross-border worker may normally be insured where they work. But if they work in Switzerland and also work from their country of residence, the social security position can change. Remote work and home-office days should be checked before the pattern is agreed.

Remote work and telework

Remote work can turn a simple Swiss employment or assignment into a multi-country social security case. The answer depends on the countries involved, the employee's residence, the employer location, and the percentage of work performed from each country.

Foreign payroll with Swiss work

Foreign payroll does not automatically keep the worker outside Swiss compliance. If the employee physically works in Switzerland, the employer should check immigration, notification, posted-worker, salary, payroll, tax, and social security rules together.

UK and non-EU/EFTA cases

A1-style social security coordination is clearest in EU/EFTA-Switzerland cases. UK cases require separate analysis because the UK is no longer covered by the Swiss-EU free movement framework in the same way after Brexit. UK-related assignments should be checked under the applicable Swiss-UK mobility and social security arrangements.

For non-EU/EFTA nationals posted by an EU/EFTA company to Switzerland, the immigration route can depend on whether the person has already been integrated into the EU/EFTA labour market for at least 12 months before the Swiss assignment. Employers should check immigration and social security together.

Legal basis: VFP Art. 2 para. 3; Swiss-UK post-Brexit mobility and social security arrangements where applicable.

Documents employers usually need

The exact file depends on the countries and assignment type. Employers usually need identity and residence status, employment contract, payroll country, sending entity details, Swiss host or client details, assignment letter, work location, start and end dates, and activity description.

For the A1 position, keep the A1 certificate, proof of application if pending, competent authority correspondence, and AHV/OASI confirmation where relevant.

For the Swiss side, keep work permit or notification evidence, posted-worker documents, salary and expense evidence, payroll and tax analysis, and any required health coverage documents such as S1 or EHIC where relevant.

Common employer risks

The biggest risk is treating A1 as work authorization. An employee may have a valid A1 and still need a Swiss work permit, online notification, or posted-worker filing before working in Switzerland.

Other common risks include missing the 8-day notification rule, calling productive work a business trip, overlooking salary and expense rules, failing to monitor remote-work percentages, having no A1 evidence during an inspection, or starting the A1 and immigration review too late.

The practical control is to run A1, immigration, payroll, tax, and posted-worker checks together before the assignment starts.

Legal basis: FNIA/AIG Art. 117 and 117a; FNIA/AIG Art. 22; VFP Art. 9.

Before the assignment starts

Before confirming travel or an assignment, employers should answer these questions:

• who employs the person?

• who hosts the work in Switzerland?

• where does the employee live?

• where is payroll located?

• what work will be done in Switzerland?

• how long will the work last?

• will the employee work remotely from another country?

• does the person need a Swiss notification or work permit?

• does the case trigger posted-worker salary or document rules?

These answers determine whether the company needs A1, Swiss notification, permit application, posted-worker documentation, payroll setup, tax withholding analysis, or several of these at the same time.

How Permitree helps

Permitree helps employers assess Swiss immigration and global mobility cases across work permits, secondments, A1 certificates, posted workers, cross-border work, payroll touchpoints, tax withholding prompts, and employer compliance.

Permitree Check is the entry point: teams can enter the facts of the case and get a likely route, timeline, document checklist, cost view, risks, and process overview before moving into the full case.

💡 Check the Swiss hire feasibility. Permitree gives employers the likely Swiss route, timeline, document checklist, costs, risks, and process overview before they move into the full hiring or mobility case.

FAQ

Legal references

Official sources

• Federal Social Insurance Office / BSV

• AHV/IV information centre

• State Secretariat for Migration / SEM

• Fedlex

• SECO

• EU social security coordination