Verona: The Control-Command and Signalling Technical Specification for Interoperability, the file that the rail industry refers to as the CCS TSI, picked up an amendment that quietly reshapes the next eighteen months of rolling stock approval. Commission Implementing Regulation (EU) 2026/693 was adopted on 19 March and entered into force on 5 May, and the European Union Agency for Railways has now published the supporting application guide. The targets are clarity, consistency and the transition between the previous and updated TSI requirements, with a particular focus on projects already deep into authorisation.
The substance lands in three places. The amendment introduces a set of new testing specifications for ERTMS components, including refinements to the methodologies that notified bodies apply during conformity assessment. It carries a parallel set of reduced specifications for cases where the full test grid is disproportionate to the technical change involved. And it puts a more precise framework around the transition regime, which is what most suppliers and infrastructure managers have been asking for since the 2023/1695 base text first started biting on live procurements.
Transition is the practical heart of the amendment. The 2023 baseline left a number of edges that projects already in flight had to manage case by case, and the result was a slow drift toward bespoke interpretations across national safety authorities. The new transition language gives suppliers a clearer way to determine which version of the specification applies to a given project depending on the stage of authorisation, and it reduces the room for diverging readings between two NSAs handling adjacent cross-border corridors. For the Brenner axis, the Rhine-Alpine corridor and the Scandinavian-Mediterranean corridor, all running ERTMS deployments in parallel, the clarity translates fairly directly into less rework on documentation.
The notified body community gets a workstream of its own. The new testing specifications will need to be folded into accreditation scopes within a transition window that the regulation defines clearly, and a number of bodies have already begun the scope extension process. The Italian, German and French notified bodies that handle the bulk of the CCS conformity assessments expect the scope updates to complete inside the first half of 2026, which keeps the approval pipeline open for procurements that were due to clear the certification gate in the second half of the year.
For railway undertakings, the operational read is mixed. The amendment does not reopen the schedule for ERTMS deployment along the core network corridors. Those obligations sit under the revised TEN-T regulation rather than the CCS TSI. But it does reduce friction in how on-board equipment is recertified after each engineering change. That is consequential for fleet operators running mixed older and newer baseline stock across borders, because the recertification overhead has been one of the larger non-obvious cost drivers on the cross-border passenger and freight networks.
Industry feedback into the amendment cycle, gathered through the ERA-led working groups, will continue to feed forward into the next CCS TSI update package, which the agency has scheduled for adoption in the second half of 2027. The intervening eighteen months are when the practical edges of the new regulation will show, and where the supplier community will surface the cases that the refresh handles cleanly versus the cases that still need a further pass. The Verona rolling stock authorities reading the new text this week are reasonably confident that the cleaner cases now outnumber the difficult ones, a reversal from where the file sat a year ago.
