What is an A1 certificate?
An A1 certificate proves which country insures you socially while you work abroad.² In the Netherlands the Sociale Verzekeringsbank (SVB), the Dutch social insurance bank, issues it and not the Belastingdienst.³ That is where most confusion starts. The certificate took over from the old E101 form.²
Social insurance is the system behind your AOW state pension, your child benefit and your unemployment cover. Two European regulations coordinate it across borders. They are the basic regulation (EC) 883/2004 and the implementing regulation (EC) 987/2009. Their main rule points at the country where you work. That is the work-country principle. Articles 12 to 16 of the basic regulation set out the exceptions.³
Take Marlon. He is a service engineer who installs production machines in Eindhoven. In March his employer sends him to a customer site in Denmark for 8 months. Does he stay insured in the Netherlands while he is there?
The panel below gives the short answers.
In short
The SVB issues your A1 certificate. The Belastingdienst does not.
An application to the SVB is free of charge.
24 months is the maximum a temporary posting can run under article 12.
Your employer applies for it. You apply yourself if you are self-employed or work in two or more EU countries.
The A1 certificate settles your insurance, never the tax on your salary.
Who needs an A1 certificate and who applies for it?
You usually need one for temporary work in an EU, EEA or treaty country. Some countries will not let you start work without it. Their labour inspectorate can fine you if you work there anyway.²
Marlon does not apply for the certificate himself. Under the European rules your employer notifies the SVB about a posting. Dutch employers file it online through TWinternet or on paper with an SVB form. The SVB then sends the certificate to the employee, because it is a personal document.³
Two groups report it themselves. Do you work in two or more EU countries at the same time? Then you notify the body where you live.³ Online you do that through My SVB with your DigiD, the Dutch government login.¹
Self-employed people apply themselves as well, through My SVB or on paper. The SVB replies to a paper application within 8 weeks.¹ Extra conditions apply to the self-employed. You have to have been working for yourself for at least 2 months before you leave. You also have to pick that work up again when you return.²
The table sets the four situations side by side. Your employer does not have to be Dutch for this to apply. Posted into the Netherlands instead? Then your home country issues the A1 certificate.
| Your situation | Which rule applies | Who applies |
|---|---|---|
| Sent abroad for up to 24 months | Article 12, the posting rule | Your employer, or you if you are self-employed |
| The posting runs past 24 months | Article 16, an agreement between the two countries | Your employer or you |
| Working in two or more EU countries at once | Article 13, the multi-state rule | You, in the country where you live |
| Moving abroad to work there for good | The main rule: your work country insures you | Nobody, you do not need an A1 certificate |
How long is an A1 certificate valid?
A temporary posting stays covered for 24 months at most.² ³ That limit comes from article 12 in the table above. Marlon’s posting is nowhere near it.
Suppose the Danish job lasted 30 months instead. His employer or Marlon himself could then ask the two countries to agree that he stays insured here. That request rests on article 16 of the basic regulation. Both countries have to agree to it.³
The difference between the two routes matters. Article 12 is mandatory law, so it applies by itself once the conditions are met.³ An article 16 agreement is the opposite, an option the two countries can grant rather than a right.³ Whether a request succeeds depends on the country involved.³
After 24 months the system of the work country applies in principle, unless the two countries agree otherwise.² ³ For a posting longer than 24 months the SVB runs extra checks first.¹ If you can stay insured here, you should have the certificate within 3 months.¹
The table below adds the practical details.
| Topic | The A1 certificate |
|---|---|
| How your employer applies | Online through TWinternet or on paper with an SVB form |
| Reply to a paper application | Within 8 weeks |
| Posting longer than 24 months | Only if both countries agree under article 16 |
| Waiting time for that request | Within 3 months, after extra SVB checks |
| Where it is valid | Only in the country or countries named on it: EU, EEA or treaty countries |
What does this look like on one posting?
Marlon keeps his Dutch cover for the whole 8 months. His posting is temporary and stays inside the 24-month limit, so article 12 applies.
His employer notifies the SVB before he leaves. The SVB assesses it and sends him the certificate. Nothing changes on his payslip. His employer keeps paying Dutch contributions, he keeps his Dutch health insurance and he continues to build up AOW. If the Danish labour inspectorate asks, the certificate is the proof.
What he takes with him is one document that answers the insurance question for the whole posting.
The application does touch his employer’s payroll administration. The box below sets out what that means for tax.
Does an A1 certificate change your tax return?
An A1 certificate changes nothing about your income tax return. It settles which country insures you. It says nothing about which country taxes your salary.
The box above was about wage and contributions, not about your return. The two questions fall under different rulebooks and can point at different countries. Social security follows the European coordination regulations.³ Tax follows the treaty between the Netherlands and the country you work in. So Marlon can hold a Dutch A1 certificate and still owe Danish tax on part of his salary. The 183-day rule for working outside the Netherlands decides which way that falls.
Three more pages pick up the tax side. Tax residency in the Netherlands decides whether the Netherlands still treats you as a resident. Double taxation in the Netherlands explains how relief works when both countries have a claim. And your worldwide income return covers what you earned abroad in a year you were a Dutch resident.
Our advisor puts the split like this.
“People expect one document to settle everything abroad. It does not. The A1 answers the insurance question and the treaty answers the tax question. I regularly see the two come back with a different country on them. That is normal rather than a mistake.”
What does this mean for you?
Make sure your employer has applied before your start date. Inspectorates in most countries also accept a copy of your application while you wait. Belgium adds one step, because it requires a Limosa registration in advance.¹
Two checks are worth running yourself. Marlon runs both before his March start. Confirm the posting length against the 24-month limit. His 8 months sit well inside it. A job that quietly grows past it needs the article 16 route. Confirm that your work country is in the EU or the European Economic Area (EEA). Denmark is, so that check passes. A country with a social security agreement also counts. The certificate only covers the country or countries named on it.
Does the same year also bring a move into or out of the Netherlands? Then that migration year has its own return.
That migration return is where we most often meet people who have worked abroad for a while.
¹ svb.nl, Apply for an A1 certificate free of charge · Accessed
² business.gov.nl, A1 certificate of coverage for social security · Accessed
³ kennisgroepen.belastingdienst.nl, KG:204:2024:3 A1-verklaring · Accessed
Common questions about the A1 certificate
Who issues the A1 certificate in the Netherlands?
The SVB is the only body that issues one here. The Belastingdienst plays no part in it. Your employer usually files the application.³