Interoperability Toolkit (ITK)


The Interoperability Toolkit (ITK) is a set of common specifications, frameworks and implementation guides that support interoperability. The ITK attempts to solve these problems by providing a number of specifications and technologies which are consistent and applicable across a wide range of domains and localities. It's not a piece of software or a downloadable product.

Individual interfaces within the Interoperability standard may require suppliers to implement in accordance with, and show compliance to, either ITK2 or ITK3.

ITK2 Requirements


The ITK standards fall into various areas including core messaging elements and supporting infrastructure, specialist additional modules, messaging transports such as TMS, DTS and its own ITK web services standard and a number of specific message standards.  Systems can become compliant under a number of different configurations, specifically ITK Middleware, ITK Spine Mini Service Provider and ITK Application. 

In the context of GP systems, the system MUST offer an ITK Application interface as a minimum and may offer additional configurations if required.


The system MUST support the following modules from  the ITK v2 ‘Application’ configuration:

  • Core Messaging
  • Supporting Infrastructure – Common
  • Supporting Infrastructure  - Application Specific
  • Additional Modules – Sequencing – Application
  • Additional Modules – IG – Application
  • Web Service Transport

ITK3 Requirements

ITK3 implements STU3 Fast Healthcare Interoperability Resources (FHIR) messaging over Messaging Exchange for Social Care and Health (MESH) with extensions to provide an acknowledgement framework.

Go to for the directory of published ITK3 Messaging Distribution versions.

Compliance, Assurance & Testing

Compliance, assurance and testing resources that support implementers of this specification can be obtained by visiting:, in particular, 'Part 4: Testing and Accrediting an Implementation'.

For further advice and support beyond what is set out above, please contact


Interoperability Toolkit homepage ITK page