The European Parliament formally adopted the revised EU rules on social security coordination on 7 July 2026, and the changes are on track to enter into force this month, once the Council of the European Union completes formal adoption. For any organisation posting employees across EU member states or running multi-state working arrangements, this is the most significant change to A1 certificate and posted-worker compliance in over a decade.
What Has Changed
The revision amends Regulation (EC) No 883/2004, the legal basis for determining which member state is responsible for an employee's social security coverage. Three changes matter most for employers:
- Extended prior affiliation requirement. Employees must now be affiliated with the sending state's social security system for at least three months before they qualify for an A1 certificate and can be posted while remaining on their home scheme. This replaces the current one-month requirement, closing off same-week hire-and-post arrangements.
- Mandatory cooling-off period. After a 24-month posting, employers must observe a two-month gap before posting the same employee back to the same member state, or before replacing them with another worker in the same role. An exceptional agreement can extend A1 validity up to five years, but only in limited cases.
- A1 must be filed before the posting starts. Applications can no longer be submitted retroactively. Where an A1 isn't issued in time, the competent institution must provide an acknowledgement of receipt, which stands as interim proof of compliance. A narrow exemption applies to business trips and short-term activities of no more than three consecutive working days within a 30-day period — though how authorities will police that window in practice is still unclear.
For multi-state workers — those working routinely across two or more member states rather than posted from one to another — the rules also extend maximum A1 validity to 24 months, based on a 12-month forward projection of travel patterns, and clarify that non-EU residents are treated as resident in whichever member state hosts most of their working activity.
What This Means for HR and Mobility Teams
The direction of travel is less flexibility, more advance planning. A hiring pattern that brings someone on and posts them within weeks no longer works under the three-month affiliation rule. Assignment planning for postings needs to start well before the move, not once a role is confirmed. Recent CJEU rulings (Case C-743/23, GKV – Spitzenverband, and Case C-203/24, Hakamp) add to the compliance bar: "substantial activity" for multi-state workers must now be assessed on a full, objective, working-time basis — not on selected contracts or management's preference for where the "centre" of a role sits.
Action Steps
- Map current and planned postings against the new three-month prior-affiliation rule before confirming start dates.
- Build the two-month cooling-off period into any assignment that involves repeat postings to the same country.
- Move A1 applications to the front of the assignment timeline — treat "posting confirmed" and "A1 filed" as the same milestone, not sequential ones.
- Separate genuine multi-state working populations from postings, and revisit which classification each current arrangement actually meets.
- Review entity structures and reporting lines against the tightened definition of "registered office" and "place of business" for social security purposes, particularly for light-footprint or holding-company setups.
xpath.global's tax and social security team tracks A1 certificate rules and posting timelines across the EU as they change, so a posting or multi-state assignment doesn't stall — or fall out of compliance — while the underlying regulation shifts. For organisations with a live population of posted or multi-state workers, now is the time to check existing A1 positions against the incoming rules rather than waiting for an inspection to surface the gap.
"Sources: Fragomen — "New EU Social Security Coordination Rules: What Employers Need to Know", 24 June 2026; KPMG GMS Flash Alert 2026-191 — "European Union – New Era for Social Security in Multi State Working", 23 July 2026; European Parliament press release — "Clearer social benefits rules for EU mobile workers", 7 July 2026."
