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Find out more about integration and how to connect systems to the NHS e-Referral Service (e-RS)

Application Programming Interfaces (APIs)

The development of the N3/HSCN based e-Referral Service APIs is influenced by RESTful service interfaces and the HL7 FHIR (Fast Healthcare Interoperability Resources) standard.

Find out more about FHIR.

What APIs are currently available?

FHIR APIs are now in use at a variety of NHS organisations across the country allowing the electronic transfer of clinical documents between e-RS and integrated clinical systems. Find out more by reading our case study about Imperial College Healthcare.

These APIs can also potentially be used by e-RS service providers who use Referral Assessment Services (RAS) to support the patient registration process.

Find out more about the guidance on using APIs with RAS.

Further APIs were added throughout 2020 which provide the ability to:

  • search for patient services via the e-RS Directory of Services (DoS)
  • create e-referrals with attachments
  • generate a patient letter
  • search for and book appointments (for directly bookable services)
  • accept or reject a referral
  • cancel an appointment request, for action later

Released in March 2021:

  • changes to the referrer APIs to allow management of referral attachments

Released in April 2021:

  • receiving advice & guidance requests, sending a response or converting to a referral (where allowed by the referrer)

Released in August 2021:

  • referrals sent to triage (RAS) services can be accepted (for booking later) or returned to the referrer with advice

Future planned developments for 2021

Further development of the e-RS FHIR APIs ensure that the service is continually improved with the goal of making it easier, quicker and more efficient for third party solutions to connect.

The e-RS roadmap includes a timetable of the planned system enhancements, including:

  • allow authentication to the APIs over the internet using NHS Identity

Find out more about the above changes from the e-RS news page.

These developments are based on your feedback.

Find out how you can provide suggestions on how to improve e-RS integration.

We aim to deliver both new APIs, as well as updating existing ones so that we can continue to provide benefit to both patients and professional users.

Appointment Slot Issues (ASI) worklist API - Now available

What is the ASI worklist API?

The ASI worklist API will provide access to the e-RS ASI worklist to connected software systems. This worklist shows all referral requests that have been "deferred" to the service provider because there were no available appointment slots in e-RS at the time of booking. These referrals can be reviewed prior to an appointment being booked by the service provider.

How will the API help users?

This API allows software suppliers to integrate the ASI worklist into their software products. The benefit to users will be the ability to see the list of ASI referrals from within the software they use day-to-day rather than accessing e-RS to view it.

The APIs can also provide information such as patient NHS number, a PDF of the clinical referral information and any attachments (including the referral letter, if provided).

An API integrated system could be enhanced to download this information and create or update its patient registration records electronically.

How do I get my software integrated to make use of this API?

If you are a software supplier you can find all the technical details on the API developer hub.

If you are an end user organisation, such as an NHS Trust or a CCG, you should contact your software supplier and inform them of your need to integrate with this API. In both cases you can get help by contacting the e-RS Partners Team at

Development and compliance

The health developer network provides all technical documentation and information on the engagement process, API architecture, setting up test environments, FHIR resources and all other development resources required to start building an e-RS integration.

Last edited: 27 July 2021 1:11 pm