Does your company temporarily post employees to other European Union countries or have employees who regularly work in several Member States?
The rules determining which country’s Social Security system should cover these employees are set to change. On 28 September 2026, the Council of the European Union gave final approval to the reform of the European rules on the coordination of Social Security systems. For companies, some of the most relevant changes concern posted workers and people who carry out their activity in two or more EU countries.
However, final approval does not mean that these new rules already apply. Below, we explain what is changing and what companies should review now.
What is changing for workers posted within the EU?
When a company temporarily sends an employee to work in another Member State, the Social Security legislation of the home country may continue to apply if certain conditions are met.
The reform maintains the general maximum posting period of 24 months established under the European rules. However, it introduces new requirements designed to strengthen oversight of postings and ensure that the correct Social Security system is applied.
One of the main changes will be the prior notification requirement. In other words, before the employee begins working in another Member State, the company will need to inform the competent institution in the country whose Social Security legislation is to remain applicable and request the relevant certification.
In practice, this certification is usually provided through the Portable Document A1, which is used to demonstrate which Social Security legislation applies.
For Spanish companies, this procedure is not entirely new. As a rule, the General Treasury of Spanish Social Security already requires posting applications to be submitted in advance using Form TA.300, after which the A1 certificate can be obtained.
Not all business trips will be treated in the same way
One of the most relevant developments for companies is that the Regulation expressly distinguishes certain business trips from other activities carried out in another country.
It defines a business trip as a temporary activity linked to the company’s business interests that does not involve providing services or supplying goods. Examples include:
- Business meetings.
- Conferences and seminars.
- Certain cultural or scientific events.
- Activities related to academic research.
- Training-related travel.
These business trips are excluded from the new general prior notification requirement.
An exception is also provided for activities lasting no more than three consecutive working days within a period of 30 consecutive days.
This second exception will not apply to the construction sector, where stricter controls remain in place due to the nature of the activity and the high volume of cross-border postings.
Companies will therefore need to assess carefully what the employee will be doing in the destination country. Attending a meeting is not the same as travelling abroad to provide a service to a client.
The link with the Social Security system of the home country will also be strengthened
The reform also introduces rules designed to prevent postings from being used solely to maintain an artificial connection with the Social Security system of another Member State.
Among other measures, a person hired specifically with a view to being posted to another Member State will need to have been subject to the Social Security legislation of the country where the company is established for at least three months beforehand.
For self-employed workers, the general requirement will also be to have carried out their activity for at least three months in the Member State where they are established.
In addition, where a person has carried out an activity in another Member State for a total of 24 months, at least two months must generally pass before the standard posting rules can once again apply to that same person in relation to the same Member State. However, exceptions may apply in certain circumstances.
What about employees who regularly work in several countries?
The first point to clarify is that not every case of international mobility involves a temporary posting.
Some employees regularly carry out part of their work in two or more Member States. In those cases, it is necessary to determine which single Social Security legislation applies.
The reform introduces clearer criteria for determining where the company’s registered office or centre of activity is located when this factor is relevant. It will no longer be sufficient to look only at a formal address.
Factors that may be considered include:
- Where the company’s key decisions are made.
- Where its central administration is carried out.
- Its turnover.
- Where general meetings are held.
- The activity it usually performs.
In addition, the determination of the applicable legislation for a person working in several Member States will have a maximum validity of 24 months. Once that period expires, the employee’s situation will need to be reviewed to confirm whether the same circumstances still apply.
This may be particularly relevant for companies with international teams whose working arrangements across different countries change over time.
When will these new rules start to apply?
The Council has definitively approved the Regulation, but it will enter into force on the first day of the month following its publication in the Official Journal of the European Union.
The reform therefore now opens a period in which companies and public authorities can adapt their procedures. Until then, the rules currently in force will continue to apply.
What should company with international mobility review?
Although these changes do not apply immediately, companies that post employees within the EU can use this period to review:
- What types of international assignments or postings their workforce currently undertakes.
- Which cases are genuine work postings, and which are business trips.
- How A1 documentation is currently requested and retained.
- Whether any employees regularly work in several Member States.
- What information is used to determine the applicable Social Security legislation.
- Whether internal procedures are in place to notify postings before they begin.
Preparing in advance for the new European labour mobility rules
The reform does not require companies to change all their international mobility procedures immediately, but it does show the direction in which European Social Security coordination is moving greater prior control, clearer rules and stronger cooperation between public authorities.
For companies with international operations, reviewing how cross-border postings are managed in advance can help prevent problems over which Social Security legislation applies or where contributions should be paid.
At LEIALTA, we support Spanish and international companies in analysing their labour and Social Security obligations when posting professionals abroad or managing teams that work across several countries.
