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Interface Mechanism 1 API standards

API standards to support the integration of your systems with any principal clinical GP system using IM1.


Use these API standards to enable your system to access GP practice systems to:

  • read patient information
  • extract information in bulk
  • enter data into your system

Each IM1 interface integrates directly with one of the existing GP practice system suppliers, currently:

  • Cegedim Vision
  • EMIS Web
  • TPP SystmOne

To consume this information, you need to "pair" with the specific unique API for each GP practice system supplier.

Patient API

Using this API, the patient or their authorised representative can do the following, if specified by their GP practice (which provides linking details to their clinical record):

  • view available appointments

  • book an appointment

  • amend or cancel an appointment

  • view their repeat medication

  • request a repeat prescription

  • amend or cancel a prescription request

  • view their medical record

  • communicate with the GP practice

Note that if your application supports NHS login, this must be in addition to the linking details provided by the GP practice.

Transaction API

Using this API, and with the patient and GP practice system's permission, in real-time your application can:

  • search for a patient

  • retrieve and update patient demographics

  • retrieve a full patient medical record

  • file data to a patient record

  • retrieve a patient consultation record

  • create a new patient consultation record

  • add a document or attachment to a consultation record

  • retrieve documents from a patient Record

  • file documents into a patient record

  • retrieve an attachment from the patient’s medical record.

  • retrieve a list of all the attachments residing in the patient’s medical record

  • retrieve a list of patients whose registration details have changed

  • retrieve the list of active users from a given organisation

  • delete data from a patient’s record

  • retrieve appointment slots

  • access diary information

  • query details of free slots in the appointment book

  • extract CSV files

Note that you might need to install a software component on the local practice machine so your application can interact with the clinical system client. This might be on one machine within the practice to act as a gateway, or on individual machines for individual access. 

Appointments data access might only be available via GP Connect - for details, see the individual supplier's Pairing and Integration Pack (PIP).

Bulk API

Using this API, with GP practice consent, your application can get daily, weekly or monthly extracts of bulk data feeds of patient or clinical system user data.

The mechanisms for delivery of data will vary by system supplier.

As the data can be up to 24 hours old, we do not recommend this API for direct patient care. Your application must make your end users aware that any data it presents can be out of date. 

The data items extracted by each provider varies. For the data items available, see the individual supplier's PIP.

Partner API

In addition, EMIS offers access to their Partner API, which is similar to the Transaction API, but also provides:

  • a single patient demographic and medical record
  • a list of patients - for example, for finding or searching for patients
  • a list of patients with appointments booked
  • a list of patients to update, and age or sex register output
  • information about the organisation or users
  • a list of patient registration details for patients that have changed since the last query
  • appointment and appointment configuration information
  • retrieval of documents from a patient record
  • filing of documents into a patient record
  • retrieval of an attachment from a patient’s medical record
  • retrieval of a list of all the attachments in a patient’s medical record
  • booking and cancellation of appointments

  • setting an appointment's status

  • viewing a patient's arrived and sent-in status

This API is only applicable with the EMIS Web GP module and to practices based within England.

Note that the EMIS Community module is not available currently via IM1. 

Specifications and onboarding

Technical specifications for the APIs are available after the supplier assesses your application to pair for feasibility. API specifications (PIPs) give the specific information available from each supplier.

There is an onboarding and assurance process for your application to use these standards, see Process.

Once assured, you join the list of assured suppliers, see IM1 live suppliers.

Before you begin any development work using these API standards, or if the functionality you wish to use is not yet available from a supplier, contact us at [email protected] to discuss your best options.

For a non-technical overview of how to build software that deals with referrals and bookings, see Building healthcare software - referrals and bookings.


These API standards are active.

API standards

For full details, see IM1 Pairing integration.

Last edited: 15 September 2023 7:51 am