EU Adopts A1 Reform: The Social Security Checklist for Postings in Europe

On 28 September 2026, the Council of the European Union formally adopted the reform of Regulation (EC) No 883/2004, the rulebook that decides which country's social security system covers someone working across EU borders. Member-state representatives in Coreper had approved the text on 23 September, and the European Parliament adopted it in July. After more than nine years of negotiation, the rules are now settled.

For HR and mobility teams, the headline is simple. The A1 certificate, which proves an employee stays in their home country's social security system while working in another member state, now has to be applied for before the work starts. Most of the new provisions are expected to apply about two years after the regulation enters into force, so there is time. The process change, though, needs to happen well before that date.

What the reform changes for posted workers

The posting rule in Article 12 keeps its basic shape: an employee can be posted to another member state for up to 24 months and stay covered at home. What changes is the detail around it.

Prior notification becomes mandatory

The A1 application must be submitted before the posting begins. The home institution issues a confirmation of receipt, and that receipt proves compliance while the certificate is being processed. If no application was made in advance, the employee does not automatically lose home-country cover, but the host state can impose administrative sanctions on the employer and start an information-gathering process that usually ends in a retroactive A1 after weeks of extra work.

The short-activity exemption is narrow

Prior notification is not required for business trips, or for other activity lasting no more than three consecutive days within a period of 30 consecutive days. A business trip means meetings, events, seminars or training. It does not cover providing services or delivering goods.

Construction has no exemption

Apart from genuine business trips, every posting in the construction sector needs a prior A1 application. The regulation defines construction broadly: excavation, assembly and dismantling, installation work, renovation, repairs, maintenance and demolition all count.

Three months of prior cover

Posted workers must have been covered by the sending state's social security system for at least three consecutive months immediately before the posting, up from one month. People hired specifically to be posted must be covered from the day their employment starts.

A two-month cooling-off period

Once a posting to a country reaches 24 months, at least two months must pass before the same person can be posted there again under home-country cover. A break shorter than two months does not interrupt a posting; it is treated as continuous.

Replacement clarified

One posted worker can replace another on the same assignment, as long as the combined posting does not exceed 24 months.

These changes sit alongside the Commission's Fair Labour Mobility package of 15 September 2026, which proposes a European Social Security Pass (ESSPASS) so that A1 certificates can be requested, stored and verified digitally. Under that proposal, the A1 would be the first document digitalised, one year after the ESSPASS regulation enters into force.

The deployment checklist

Use this before any employee starts work in another EU country. It covers the social security side; the immigration and tax checks run in parallel.

Step 1 is where most errors begin. An engineer "visiting a client" may be attending a meeting, or may be commissioning a machine. The first is a business trip. The second is service delivery, and if it runs past three days, or touches a construction site, it needs a prior A1.

What this means operationally

The reform moves social security from an after-the-fact task to a gate in the approval process. In practice, three things change for HR and mobility teams.

Lead time

A1 processing times vary widely between member states, from a few days to several weeks. If line managers give mobility teams two days' notice before sending someone abroad, the filing can still be made, but only if the classification and the prior-cover checks are already built into the request.

Records

The three-month prior cover rule, the cooling-off period and the replacement rule all depend on history: who went where, for how long, and who replaced whom. Teams that track postings in spreadsheets maintained by different business units will find these rules hard to apply consistently.

Project workforces

Employers running construction, installation and plant projects across Europe are most exposed. Their staff rotate often, their work usually counts as construction, and short stints that used to be handled informally will now need a filing every time.

For some employers, the cleaner answer is to stop posting altogether for longer roles and hire locally through an Employer of Record, which puts the employee on local payroll and local social security from day one. That trade-off depends on assignment length, cost and how often the same people move between countries.

How xpath.global supports EU postings

xpath.global manages A1 applications as part of the assignment plan, alongside Posted Workers Directive notifications, work permits for third-country nationals and Employer of Record hiring across Europe. Each posting sits in one case on the xpath.global platform, with its dates, prior-cover check and filing receipts, so the 24-month limit and cooling-off gaps are visible before they become a problem.

If your teams post staff across the EU, now is a good time to test your approval process against the checklist above.

Sources: Council of the European Union, voting result 13678/26 — 28 September 2026; Remote Work Europe — 23 September 2026; Council of the European Union, amended regulation text ST 8387/26 ADD 1 — 23 April 2026; European Commission, Fair Labour Mobility package — 15 September 2026.