The Council of the European Union published proposed changes to EU social security coordination rules on 23 April 2026, with the revised framework expected to take effect in September 2026 after adoption in July — tightening exactly the requirements employers most often get wrong on A1 certificate applications.
What Has Changed
Posted workers must now have been covered by social security in the sending state for at least three consecutive months immediately before being posted to another member state. Workers hired specifically with a view to being posted must already be covered by the sending state's social security system at the point their employment begins — closing a gap where employment and posting could start almost simultaneously.
A new two-month cooling-off period applies after a 24-month posting, before the same worker can be posted to the same host country again. This directly targets a pattern used to extend postings indefinitely through back-to-back assignments.
A1 certificate validity remains tied to the determination of applicable legislation, which can run up to 24 months. The reformed rules for posted and multistate workers carry a 24-month transitional period before full implementation — giving employers a runway, but not an indefinite one.
What This Means for HR and Mobility Teams
The three-month prior coverage rule changes hiring sequence for any role designed as a cross-border posting from day one. An employee hired and posted within weeks of their start date will likely fail the new test unless the sending-state coverage requirement is met first.
The cooling-off period affects long-running assignment chains — organisations that rotate the same specialists through the same country on consecutive contracts need to build a genuine two-month gap into planning, not a paper one.
Multistate workers — those regularly working in two or more member states — sit inside a coordination framework that is also being revised, meaning A1 determinations for this group deserve a fresh look rather than automatic renewal.
Action Steps
- Sequence hiring and posting dates so any new posted worker clears three months of sending-state social security coverage first.
- Map current assignment chains for anyone approaching 24 months in a host country and schedule the two-month cooling-off period into the transition plan.
- Review A1 certificates for multistate workers against the revised coordination rules rather than assuming prior determinations carry forward unchanged.
- Track the 24-month transitional window — plan for full compliance well before it closes, not at the deadline.
xpath.global's tax and social security team manages A1 certificate applications and posted-worker compliance across the EU, tracking coordination rule changes so postings are structured correctly from the first day of employment. [Speak to our team.](https://xpath.global)
"Sources: KPMG GMS Flash Alert — 2026; Fragomen — 2026; Lewis Silkin — July 2026."
