Reform of the EU Social Security Coordination Rules:

On 28 September 2026, the Council of the European Union formally adopted the revision of Regulations (EC) No 883/2004 and No 987/2009, which coordinate the social security systems of the Member States. Unemployment, long-term care, family benefits and access to social benefits for economically inactive persons are also affected.

For international mobility, the impact is concentrated on the rules that determine the applicable legislation. They decide in which country contributions are due and when an A1 certificate is required. Three situations are covered: postings, business trips and activity in several countries.

The principles do not change, but their application is tightened: more formalities before departure, stricter conditions for posting and, in return, the first European definition of a business trip. For Switzerland, nothing changes at this stage: the text will first have to be taken over into the agreement between the EU and Switzerland.

Postings: more checks before departure

Four changes give postings a tighter framework.

Notification before departure

The employer must inform the competent institution of the sending State and request the A1 certificate before the activity begins. If the certificate is not issued immediately, an automatic acknowledgement of receipt proves that notification was made. Member States may take proportionate measures against a defaulting employer, but a failure to notify does not automatically change the applicable legislation, and an A1 can still be issued retroactively.

Three months of prior affiliation

An employee recruited with a view to being sent abroad must have been subject to the legislation of the State where the employer is established for at least 3 months before starting employment, compared with 1 month today.

A break after 24 months

After 24 months of posting in the same State, even if interrupted by gaps of up to 2 months, a break of at least 2 months will be required before posting again to that State. A derogation remains possible in particular cases.

Capped replacements

If an employee does not complete an assignment and another replaces them, the total cumulative duration may not exceed 24 months. The aim is to prevent a position from being artificially kept under the posting regime.

In practice, the A1 certificate comes into play as soon as a departure is being prepared. Postings must be identified at the planning stage, the employee’s affiliation checked and the application filed on time. A recently recruited employee may no longer meet the affiliation condition.

Business trips: finally defined, but still to be qualified

For the first time, European law defines the business trip, and such a trip does not require an A1 certificate. It is a temporary, time-limited activity linked to the employer’s business. Meetings, conferences, seminars, cultural or scientific events and training received fall within it, whereas the provision of services and the delivery of goods are excluded.

A second exemption covers activities of no more than 3 consecutive days of work within a period of 30 consecutive days, except in construction. In both cases, the employer does not have to notify the institution in advance or apply for the A1 certificate.

The simplification has a limit, however: each trip must still be qualified. An employee sent to perform a service at a client’s premises falls outside the definition, and it must then be examined whether this is a posting. A trip that needs no A1 for social security purposes may also create tax or immigration obligations, which follow their own criteria.

Several countries: 25% threshold maintained, criteria clarified

The 25% threshold of activity in the State of residence remains unchanged. The text does, however, clarify how to determine the place where the employer is established, and therefore the applicable social security legislation. It is the place where the company’s essential decisions are taken and where its central administration functions are exercised.

This place is determined by an overall assessment of each situation, not by a single criterion. Turnover, the place of general meetings and the habitual nature of the activity are cited as examples of factors, but the list is not exhaustive. The Administrative Commission still has to set out the detailed arrangements.

The duration of certificates also changes. The first A1 for multi-state activity will be issued for a maximum of 24 months, based on the situation expected for the following 12 months. At the end of that period, the applicable legislation is reassessed and the certificate may be renewed if circumstances remain unchanged.

Open-ended certificates and certificates of longer initial duration disappear. Another novelty: a person residing outside the Union and working in several Member States will be deemed to reside in the State where they carry out the majority of their activity within the Union.

In all cases, day tracking remains central. Remote work, meetings and other activities carried out in the State of residence must be documented, in order to confirm the applicable legislation and secure the A1.

Switzerland: no automatic takeover

Since 1 April 2012, Switzerland has applied Regulations 883/2004 and 987/2009 in its relations with the EU, through Annex II of the Agreement on the Free Movement of Persons (AFMP). The revision will not apply there by itself, even though the regulation is flagged as being of interest to Switzerland. According to SECO, there is no legal obligation for Switzerland to take it over.

Takeover would go through a decision of the AFMP Joint Committee, which Switzerland would have to approve expressly. The usual domestic approval procedure applies, including a possible referendum. Until then, the current rules continue to apply between Switzerland and the EU.

A negotiable takeover, but not without risk

At the Joint Committee, Switzerland could negotiate the terms of a takeover, for example transition periods or specific arrangements. A refusal remains possible, but the EU could respond with countermeasures that are hard to predict. Without takeover, the current version of the regulations would remain in force, at the price of markedly more difficult social insurance coordination.

The Switzerland–EU package (Bilaterals III) does not settle this case, because the revision had not been formally adopted when the negotiations took place. It does, however, provide for dynamic takeover of relevant law into the AFMP, never automatic and always subject to national approval.

Once the package is in force, if the Joint Committee fails to agree and Switzerland refuses, the EU could refer the matter to an arbitration tribunal. If the tribunal finds an unfulfilled obligation to take over the law, the EU could adopt proportionate compensation measures, which Switzerland can have reviewed. The current agreement, by contrast, has no dispute settlement mechanism.

Unemployment of cross-border workers: the point of friction

On the Swiss side, the most sensitive issue is unemployment benefit for cross-border workers. Under the revision, the country of last employment would pay benefits to wholly unemployed cross-border workers after 22 uninterrupted weeks of activity, instead of the country of residence. SECO estimates the additional cost for Swiss unemployment insurance at between CHF 500 and 800 million, with a high degree of uncertainty.

Earlier estimates, still cited in the debate, put it at 600 to 900 million. On 17 September, the National Council adopted, by 109 votes to 72, a motion from the Swiss People’s Party (SVP) asking the Federal Council to refuse this takeover. The Federal Council considers it premature to decide, and the motion binds it only if the Council of States adopts it too.

A calendar still open

The regulation must first be published in the Official Journal of the EU. The EU can then place the takeover on the Joint Committee’s agenda, with no date set.

The Switzerland–EU package is moving forward in parallel. Signed in its main elements on 2 March 2026, it was debated in the Council of States from 28 September to 1 October. On 30 September, the Council of States voted by 23 to 17 in favour of a referendum requiring a double majority of the people and the cantons on the stabilisation part, against the advice of the Federal Council. The National Council still has to decide.

For companies operating on both sides of the border, the European rules and those applicable with Switzerland could therefore diverge for a time.

24 months to prepare

No immediate change of process is required. The regulation will enter into force on the first day of the month following its publication in the Official Journal of the EU, which is still to come. Most of the new rules, including those on postings, multi-state activity and A1 certificates, will apply 24 months after that entry into force, with the exception of a few technical provisions.

Ongoing situations benefit from a transitional regime. Postings that started before the date of application remain subject to the old version of Article 12. For other cases where the applicable legislation would change because of the reform, the old legislation continues to apply as long as the situation remains unchanged, for no more than 10 years after entry into force.

This time can be put to use right now. 

Six workstreams can be opened without waiting:

• Map current and planned mobilities: postings, frequent travellers, employees active in several countries.
• Review existing A1 certificates, in particular those for multi-state activity, whose initial duration will be capped at 24 months.
• Build the 3-month affiliation check and the prior notification into the departure process.
• Put in place a grid for qualifying trips (business trip, posting, multi-state activity) that takes the tax and immigration aspects into account.
• Track days by country, remote work included, continuously rather than after the fact.
• For flows with Switzerland, follow the Joint Committee’s decision and the Swiss political calendar; the current rules remain applicable until then.

The reform will ease some cases, especially short trips, but it shifts the effort towards anticipation and documentation. We will follow the takeover between Switzerland and the European Union closely and will come back to it in a forthcoming newsletter.