The European financial industry is collectively entering a new stage in its journey to T+1 settlement, due on 11 October 2027. As market-wide testing, set to begin in 2027, draws closer on the horizon, stakeholders are moving beyond individual preparation and beginning to connect to coordinate readiness efforts.
Against this backdrop, Euronext is pleased to release two documents that further its High-level impact assessment, published in March 2026: a High-level test strategy and readiness plan, and Client Specifications for T+1-related changes across Euronext Clearing and Euronext Securities.
High-level test strategy and readiness plan
Euronext’s High-level test strategy and readiness plan, developed in line with the joint EU, UK and Swiss T+1 Testing Plan, outlines the programme’s working principles, testing phases, and approach to client readiness. It aims to provide an initial framework that firms can incorporate into their own planning ahead of the 2027 industry testing phase.
The strategy spans Euronext's trading, clearing and settlement activities, offering an integrated approach with location-specific adjustments where relevant. More granular materials, such as test documentation, test cases, and participant guidance, will follow in subsequent releases in Q4 2026 and Q1 2027.
Client specifications
The Client specifications build on the findings of the March 2026 impact assessment with further technical and operational detail, setting out the specific changes participants can expect ahead of go-live. Separate documents have been published by Euronext Securities CSDs and Euronext Clearing.
For Euronext Securities’ CSDs, this is the first in a series of planned releases. Updated versions are scheduled for September and December 2026, with technical parameters that will continue to be refined as both Euronext and the industry continue to make headway in their preparation.
Recent publications from the EU T+1 Industry Committee
The publications released by Euronext sit within a broader industry momentum that has been building throughout the first half of 2026.
The first is the T+1 Handbook, now available in an updated edition, which provides expanded guidance for firms across the settlement value chain.
The second is a set of FAQs and Best Practice guidance on the Gating Event, addressing one of the key operational changes that participants will need to prepare for under T+1. Designed as a practical guide, the document answers frequently asked questions on how the Gating Event operates in practice and sets out best-practice recommendations on appropriate use cases and those to avoid.
The third is the Additional Guidance: Standards for the storage and exchange of SSIs, which clarifies standards relating to the storage and exchange of Standard Settlement Instructions (SSIs) in securities transactions. Published as an addendum to the EU T+1 SSI Taskforce SSI Market Practice released in December 2025, this guidance aims to address industry concerns around potential misalignment between UK and EU practices in this area.
Euronext remains actively engaged in the Industry Committee's work and continues to contribute to this collective effort alongside industry peers.
Clients can find the relevant documentation in their usual client spaces.