With additional client and testing documentation published in September and October 2026, Euronext’s T+1 Programme continues to advance and to support its clients’ preparation. This provides an opportunity to share an update on the progress of Euronext’s T+1 Programme and the industry's overall readiness.
Euronext T+1 Programme update
Client specifications
Euronext's transversal T+1 Programme is progressing in line with its timeline. Following the high-level impact assessment shared in March 2026, Euronext published its client specifications for Euronext Clearing and Euronext Securities on 30 June 2026. They provide technical and operational guidance on each of the areas affected by T+1.
This guidance has been further supplemented by additional documentation published in September and October 2026. The latest releases provide:
- additional client specifications covering local settlement functionalities
- further guidance on operational considerations related to the management of corporate events.
T+1 testing communications
Communication regarding testing is also moving forward. Euronext Clearing has confirmed that the shaping functionality (which splits settlement instructions, including same-day repo transactions, into one or more instructions of up to €50 million in securities nominal, with a pro rata cash amount) will be made available for testing from Q4 2026, ahead of the other T+1-related changes.
For the remaining features, building on the harmonised testing strategy shared across Euronext's entire value chain in June 2026, a client test plan will be published by the end of the year, with a per-window breakdown. This will be furthered in 2027 with a list of recommended functionalities for participants to test and a list of ISINs available for testing.
These publications run alongside a continuous dialogue between Euronext and the market. National working groups and information meetings, in the local markets where Euronext operates, cover both transversal updates and national specificities related to T+1.
Euronext will continue to support its clients across the entire value chain, from trading to settlement, as they make progress on their preparations. This ongoing collaboration will help ensure that the market is fully ready for the October 2027 milestone.
The industry is moving from implementation to testing
At the start of the year, the EU T+1 Industry Committee (IC) reminded the market that 2026 would be the year of implementation. Over the first three quarters, participants put formal implementation plans in place and made advances on automation and internal testing. This groundwork sets the foundation for 2027, when the five industry-wide testing windows will offer the opportunity to test end-to-end and to validate the internal testing carried out beforehand.
Making the most of these windows will depend on the readiness of the entire value chain, and progress remains uneven, notably on the buy side. To help the market prepare for this next phase, the IC and other European bodies have continued to publish practical recommendations on implementation and testing:
The IC has released several key deliverables between June and October 2026:
- the second edition of its T+1 Handbook
- a T+1 Checklist translating the roadmap's recommendations into concrete actions
- the results of its second Readiness Survey
- an Allegements Market Practice document
- the second version of its Testing Plan.
The European Central Bank (ECB) has published a comprehensive set of corporate events implementation materials:
- an overview of the Corporate Events Adaptation Plans
- the Corporate Events Test Cases
- an updated version of the Harmonised Implementation Guide.
The European Central Securities Depositories Association (ECSDA) launched its CSD Readiness Dashboard in June 2026. The dashboard, which is updated quarterly, provides visibility on preparedness across European CSDs, with the next update scheduled for the end of October.
With go-live now a year away, this guidance comes at the right time, as the industry's focus shifts to testing. Euronext is fully integrated into these ongoing conversations, ensuring that its own timeline remains aligned with its clients' readiness needs. Euronext’s Chiara Rossetti and Paolo Carabelli will contribute to this dialogue at the IC’s “One Year to T+1” event on 29 October 2026, which will look at the road towards T+1 go-live.