A1 certificate and social security across borders

The main rule, and what the A1 does

Within the EU, the EEA and Switzerland, Regulation (EC) 883/2004 decides which country's social security applies. Only one country's legislation applies at a time. The main rule is the country where the work is done. The exceptions are posting (Article 12) and work in two or more countries (Article 13).

The A1 certificate states which country's legislation applies, and the authorities of other member states are bound by it. It covers social security only. Where wage tax is due follows from the tax treaty, and employment law rules are separate.

Posting: Article 12

• An employee who normally works for you in one member state stays insured there while working temporarily in another, if the work is expected to last no more than 24 months
• The employee is not sent to replace another posted worker
• Your company normally carries out substantial activities in the sending country, not only internal management
• An employee hired for the posting must have been insured in the sending country just before it. One month counts as enough
• Self-employed: the same 24 months, if the business has been active for at least two months and continues in the home country
• Longer than 24 months: only through an exception agreed between the two countries (Article 16), as a rule up to five years in total

Working in two or more countries: Article 13

• The employee works at least 25% in the country of residence, measured by working time or pay over the next 12 months: insured in the country of residence
• Less than 25% there, for one employer: insured in the country where the employer has its registered office
• Employer established outside the EU: insured in the country of residence
• Cross-border telework: under the framework agreement, an employee who teleworks less than 50% of the time from the country of residence can, on request, stay insured in the employer's country, where both countries have signed it

Work in two or more countries must be reported to the institution in the country of residence, which decides. In the Netherlands that is the SVB.

Who applies, and where

• Posting from the Netherlands: the employer applies to the SVB. Online through TWinternet with eHerkenning (the Dutch business login) if your company is established in the Netherlands, otherwise on the SVB's paper form
• Self-employed from the Netherlands: through My SVB with DigiD (the Dutch government login), or on paper
• Posting to the Netherlands: the employer applies to the social security institution in its own country. That institution issues the A1, not the SVB
• Work in two or more countries: through the institution in the country where the employee lives
• Apply before the work starts. According to the SVB, inspectorates in most countries accept a copy of the application while it is pending

The SVB issues the A1 free of charge. You can apply yourself; an adviser is not required.

Outside the EU: social security agreements

The Netherlands has social security agreements with countries such as the United States, Canada, Japan, India, Australia, South Korea, Morocco and Turkey. Each agreement has its own posting rules and its own certificate of coverage, and the maximum posting period differs: for example 60 months for the United States, Canada, Japan and India, and 12 months with a possible extension for Morocco and Turkey. For the United Kingdom, the protocol on social security in the EU-UK Trade and Cooperation Agreement applies, with postings of up to two years. Without an agreement there is no certificate, and the Dutch rules decide whether Dutch contributions are due.

What it means for contributions

If Dutch social security applies, the employer withholds and pays Dutch contributions through the payroll tax return:

• National insurance contributions (AOW, Anw, Wlz): 27.65% in 2026 on the wage up to € 38,883, so at most € 10,751 a year. They are combined with the wage tax in the first bracket
• Employee insurance contributions, paid by the employer, on the wage up to € 79,409 in 2026
• The employer's healthcare contribution (Zvw): 6.10% in 2026 on the wage up to € 79,409

If an A1 from another country applies, none of these Dutch contributions are due, and the employer pays the contributions of that country instead. Dutch wage tax can still be due; that follows from the tax treaty.

Posting workers to the Netherlands: also notify

An employer from the EEA or Switzerland that posts workers to the Netherlands notifies the posting before the work starts, through the online notification portal of the Dutch government (postedworkers.nl). The notification states, among other things, the country where social security is paid. It is separate from the A1, and the Dutch client checks it.

What else a foreign company with work in the Netherlands arranges, such as its VAT registration and payroll, is set out on Dutch VAT for foreign businesses.

Example

A Belgian installation company posts an engineer to a project in Rotterdam for 14 months from 1 January 2026. The engineer has worked for the company in Belgium for years and earns € 60,000 a year.

• Expected duration under 24 months, no replacement of another posted worker, and the company works normally in Belgium: Belgian social security continues
• The company applies for the A1 in Belgium and notifies the posting on the Dutch portal before the work starts
• With the A1, no Dutch national insurance contributions (27.65% of € 38,883 = € 10,751), no Dutch Zvw contribution (6.10% of € 60,000 = € 3,660) and no Dutch employee insurance contributions
• The Belgian contributions continue. Whether Dutch wage tax is due is a separate question under the tax treaty between Belgium and the Netherlands

This is a worked example, not a client case.

What we do

We work out which country's social security applies, under the Regulation or the agreement, and what that means for your payroll. For a posting from the Netherlands we prepare the application and file it with the SVB, through TWinternet with your authorisation or on the paper form: € 95 per employee per posting, excl. VAT. For work in two or more countries we test the 25% rule and the employer's seat, and prepare the report to the institution in the country of residence: € 145 per employee. For an employee coming to the Netherlands we check the A1 from the home country against the work here and arrange the Dutch payroll side: € 95 per employee.

The SVB charges nothing for the A1 itself. You pay us for the assessment and the paperwork.