It is Monday morning. Your sales lead flies to Munich for a two-day client workshop, a developer joins a conference in Antwerp, and a project manager starts a six-week assignment at a customer site in Lyon. Three trips, three very different situations. Under the new EU social security rules, they will each be treated differently, and the A1 certificate sits at the centre of it all.
On 28 September 2026, the Council of the EU gave its final approval to the revision of the EU social security coordination rules, following the European Parliament’s vote in July. The reform amends Regulations (EC) No 883/2004 and No 987/2009. It brings new conditions for postings, a formal definition of a business trip, a clearer A1 procedure and stronger enforcement. Not everything changes at once: most of the employer-facing changes only apply after a 24-month transition period. That gives you time, but only if you use it.
| Key Takeaways: – A new legal definition of “business trip” separates conferences, meetings and training from client work. – After the transition period, you request the A1 certificate before the activity abroad starts. – Business trips and activities of up to three consecutive working days within 30 days will be exempt from that advance request (not in construction). – Employees recruited with a view to posting need at least three months of prior coverage in the sending country. – After 24 months in the same country, a two-month gap is needed before a new posting. – Most of these changes apply 24 months after entry into force, which is likely to be around late 2028. |
Where it goes wrong today
Ask any HR or payroll team about A1 certificates and you will hear the same frustrations. Employees book their own travel and nobody checks whether an A1 is needed. A certificate is requested after the trip, because the trip was decided on Friday afternoon. Or an employee who works almost entirely in the Netherlands is placed on a multi-state A1 simply to cover a handful of trips to Belgium and Germany, because that is the easiest route administratively.
These shortcuts usually work, until a labour inspector at a client site in France asks for proof of social security coverage, or a foreign authority questions why an employee is insured in the Netherlands at all. At that point, the question is no longer whether you have a piece of paper. It is whether that paper matches what the employee actually does.
Most companies we speak to are not doing anything wrong on purpose. They found a practical way to handle travel and stuck with it. The new rules reward companies that know why their people are abroad, not just where they are. Those who use the next two years to tidy up their A1 processes will barely notice the switch.
How EU social security coordination works today
There is no single European social security system. Every Member State has its own, and EU law coordinates them so that a person working across borders is insured in one country at a time. The aim is to avoid both double contributions and gaps in coverage.
For an employee working in one country, the rule is simple: the country where the work is done applies. Two exceptions matter most in practice.
Temporary posting. When you send an employee to another Member State temporarily, they can, under conditions, stay insured in the sending country for up to 24 months. A Dutch employee working on a project in Belgium for six months can stay in the Dutch system. The A1 certificate is the proof. In the Netherlands, the Sociale Verzekeringsbank (SVB) issues it, and other Member States are in principle bound by it while it is valid.
Working in two or more Member States. Different rules apply when someone normally and structurally works in several countries. Think of an employee who lives in Belgium and works three days a week in the Netherlands and two days from home. The key question is whether a substantial part of the work, generally 25% or more of working time and/or pay, happens in the country of residence. If so, that country’s system usually applies. If not, the employer’s place of business becomes decisive.
What changes for the A1 certificate and postings under the new EU rules
The reform does not replace this system. It adds conditions, sharpens definitions and tightens procedures. These are the changes employers should know about.
A legal definition of a business trip
For the first time, the rules define a business trip: a temporary, time-limited activity linked to the employer’s business interests that does not involve providing services or delivering goods. The definition explicitly includes business meetings, conferences, seminars, cultural and scientific events, and receiving training.
So your developer at the Antwerp conference is on a business trip. Your project manager running a six-week implementation in Lyon is not: that is service delivery and, in principle, a posting. The purpose of the trip now matters as much as its length.
Three months of prior coverage before a posting
If you recruit someone specifically to send them abroad, that person must have been insured in the sending country for at least three months immediately before their employment starts. Hiring someone on a Dutch contract on Monday and sending them to Germany on Tuesday will not, by itself, keep them in the Dutch system.
A two-month gap after 24 months
Once an employee has been posted to the same country for a total of 24 months, with interruptions of no more than two months, the posting rules cannot be used again for that country until at least two months have passed. For companies running long projects or rotating the same specialists to the same client, this needs to be in the planning. Member States can still agree on an exception in specific cases.
The A1 certificate must be requested before the work starts
After the transition period, the employer must inform the competent institution and request the A1 certificate before the activity abroad begins. If the certificate is not issued straight away, the institution sends an automatic acknowledgement of receipt, which serves as proof that you notified in time. Applying after the fact, as often happens today, will no longer meet the rules.
Two exemptions apply to this advance procedure:
- Business trips within the new definition.
- Very short activities of no more than three consecutive working days within a period of 30 consecutive days. This exemption does not apply to the construction sector.
Keep in mind that these are exemptions from the procedure, not from social security itself. The employee is still covered by the applicable rules during the trip. And if an inspector asks, you must be able to show either the acknowledgement of receipt or evidence that the activity falls under one of the exemptions.
What about A1s for employees working in multiple EU countries?
This is where we expect the most questions. Many companies currently cover frequent business travel by including a small percentage of foreign workdays in a multi-state A1 application. It is convenient, and it may well be correct in some cases.
The new framework draws a clearer line between business trips, temporary postings and genuine multi-state work. An existing multi-state A1 is not automatically wrong, but it is worth asking: does this employee really have a normal, recurring pattern of work in several countries? Or are these individual business trips, or short postings, that would be classified differently?
Two further points matter here. Once the new rules apply, a multi-state determination is valid for a maximum of 24 months, based on the expected situation for the next 12 months, and is then reassessed. And for many frequent travellers, the business trip exemption may turn out to be the simpler and more accurate route.
Stronger enforcement and a definition of fraud
The reform is not only about simplification. It introduces a legal definition of fraud: any intentional act or omission aimed at obtaining benefits or avoiding contributions contrary to the rules. It also strengthens cooperation and data exchange between national authorities, including the planning of inspections. The construction sector gets extra attention, which is why the short-activity exemption does not apply there.
The practical message is simple: an A1 application should reflect where, why and how the employee actually works.
When do the new A1 certificate rules apply?
The amending Regulation enters into force on the first day of the month after its publication in the Official Journal of the European Union. Publication is the next formal step.
- From entry into force: the new definitions of business trip and fraud.
- 24 months after entry into force: the advance A1 procedure, the exemptions for business trips and very short activities, the three-month prior coverage rule, the two-month gap and the 24-month review of multi-state determinations.
Do not stop requesting A1 certificates for business trips as soon as the Regulation enters into force. The exemption only applies after the transition period. Until then, the current practice remains.
How employers can prepare for the new A1 certificate rules
You do not need to overhaul every international arrangement tomorrow. You do want to know where your risks are before the new procedures become mandatory. Start with employees who:
- travel frequently under a multi-state A1
- regularly work from another EU Member State
- are posted to foreign clients or group companies
- were recruited shortly before an international assignment
- return to the same country for long assignments
Then look at your travel process. Does your booking or expense system record why someone travels, not just where? Three days in Belgium can mean a conference, an internal meeting, client work or structural remote work, and each of those leads to a different analysis. If that information is missing today, the transition period is the time to add it.
Employers should review their current processes for managing employees working across borders and ensure they have the right procedures in place to meet social security and other compliance requirements. For companies with internationally mobile employees, global mobility support can help address the wider tax and compliance implications of cross-border work.
The takeaway
The core principle stays the same: one employee, one social security system at a time. What changes is that the rules now clearly separate business trips, temporary postings and genuine multi-state work, with stricter conditions and stronger enforcement. The 24-month transition period is your window to get your A1 certificate processes in order before the new procedures become mandatory.
Dutchtaxadvice helps companies and internationally mobile employees with Dutch and EU social security, including A1 applications, cross-border employment and international payroll. Not sure how the new rules affect your team? We will review your current arrangements and tell you what needs to change, and what does not. Book a free intro call.
Sources
- Council of the EU, press release 28 September 2026: Social security coordination: Council gives final green light to updated rules
- Final text of the amending Regulation, PE-CONS 29/26 (9 September 2026): data.consilium.europa.eu
- Regulation (EC) No 883/2004 on the coordination of social security systems: EUR-Lex
- Regulation (EC) No 987/2009, implementing Regulation: EUR-Lex
- Sociale Verzekeringsbank, A1 certificate for employers: svb.nl
FAQ about the A1 certificate
Do I still need an A1 certificate for a business trip?
For now, yes. The current rules continue to apply until the end of the 24-month transition period. Only after that does the exemption from the advance A1 request for business trips apply.
Is a two-day client visit a business trip?
Not necessarily. If the employee provides services or delivers goods, it falls outside the business trip definition. It may still fall under the exemption for activities of up to three consecutive working days within 30 days, unless it concerns construction.
Is our current multi-state A1 still valid?
An issued A1 remains valid for the period stated on it. The question is whether the arrangement still fits once the new rules apply. Use the transition period to check it.
What happens if we notify too late under the new rules?
The requirement is to notify and request the A1 before the activity starts. Late notification may create compliance and evidentiary issues, particularly during an inspection, but does not automatically change the applicable social security legislation.
About the Author
Mark Bastiaans is the Managing Director of Dutch Tax Advice. He graduated from Tilburg University in 2006 and previously worked at Big Four advisory firms and multinational enterprises. He specialises in international tax for expats and entrepreneurs in the Netherlands.
