Clinical layer 

In order to achieve a fully functioning and integrated system that works seamlessly between services, professional standards for digital care records must be upheld. These standards have been formalised in collaboration with clinicians and other healthcare professionals, providing a framework to follow for things such as inpatient and daycase discharge, emergency care discharge and outpatient letters.

Terminology layer 

As all NHS healthcare providers in England are contractually obliged to use SNOMED CT, Transfer of Care structured messages have the capability to include encoded information. Where this capability does not exist, organisations must show they have plans in place to achieve capability at the earliest possible opportunity.

Technology layer 

As FHIR is the international industry standard for integration, it has been adopted for Transfer of Care rather than migrating in the future, which would increase clinical risk and the cost of delay.

Transport layer 

MESH allows organisations to transfer data files securely via the NHS Spine infrastructure, and strictly prohibits other forms of electronic transport approaches being used, such as fax or email for Transport of Care message types.

Message layer

ITK3 provides the message distribution and application-level acknowledgement standard for Transfer of Care. To reduce the workload of staff at GP practices, application-level responses are automatically generated, and staff in secondary care settings must handle these responses and notify staff where necessary.