Directive (EU) 2016/797 on the interoperability of the rail system within the European Union defines ‘technical specification for interoperability’ (TSI) as a specification covering a subsystem or part of a subsystem to meet the essential requirements and ensure the interoperability of the Union rail system. For the purpose of this Directive one functional area of the Union rail system is telematics applications for passenger and freight services.

The Telematics TSI (TEL TSI) concerns the telematics applications in the EU rail system, covering both passenger and freight services. It sets common requirements for interoperable data sharing across processes such as capacity management, train preparation, traffic management, ticketing, and freight / intermodal logistics, supported by standardized APIs / data presentation, cybersecurity measures, and open data principles.

The TEL TSI is directly applicable across all Member States and binding on all stakeholders. As of 2 March 2026, it replaces the repealed legislation previously known as the TAF and TAP TSIs.

Telematics TSI (TEL TSI)