An A1 certificate (EU social-security coverage) is an official document that states the country in which an employee is covered by social insurance when they work temporarily in another EU country, EEA country or Switzerland. The social-security authority of the country where the employee normally works issues this certificate. This prevents double payment of contributions. The A1 certificate determines where you pay social-security contributions, not where you pay payroll tax.
Although the document seems simple, strict conditions apply. If you do not use the certificate correctly, or do not check it fully, you run the risk as an employer or main contractor of additional assessments, liability and chain risks.
Legal framework
Employees are usually covered by social insurance in the country where they work.
In the case of temporary posting, the social-security system of the country of residence may continue to apply.
The posting lasts a maximum of 2 years. You can extend this to 5 years if the country of employment approves it.
The scheme applies only if the employee was already covered by social insurance in the country of residence.
Conditions for granting an A1 certificate
You receive an A1 certificate only if you meet these conditions:
The employee has been covered by social insurance in the country of residence for at least one month before the posting
The employer has substantial business activities in that country of residence (a registered-office address alone is not enough)
The posting is temporary
The employer must request the A1 declaration well before work begins. If this is not possible? As an Assessor, you can then request proof of application. You can then provisionally approve it with an expiry date of approximately 4 weeks, after which you request the actual A1 declaration.
Always check the A1 certificate for:
The correct name of the employee
A valid period of validity (not expired)
The purpose: posting or working in multiple member states
The correct name of the employer
The specific work location or workplace
Where possible, use a specific work location or project name rather than a general description such as 'working in the Netherlands'. This helps during inspections.
Take care with hiring-in and on-hiring
In hiring-in and on-hiring arrangements through intermediaries, the A1 certificate may be invalid. If there is no direct relationship between the original employer and the hiring party in the country where the worker is posted, social insurance is compulsory in the country where the worker is posted, with fiscal and legal consequences.
In summary
The A1 certificate prevents double payment of contributions in cross-border work. Always check and use the document carefully. Incorrect use can lead to chain liability, additional assessments and reputational damage. Make sure you have a clear process for assessing and recording A1 certificates.