What is NHS IM1 – Interface Mechanism?

Interoperability has been something high on the agenda of the NHS for a while now.

With digital technology playing a more prominent role in patient treatment and new models of care emerging, there’s an obvious need for the better sharing of information across different systems.

In recent years, the NHS has placed a huge amount of resources behind embracing innovative technological solutions, including NHS app integrations and NHS login integrations, as better connected IT systems will help drive improvements in patient care.

One of these innovations is IM1 pairing integration. It’s a tool that enables digital suppliers to talk directly to GP clinical systems (such as NHS GP Connect), both reading patient data and putting data into the systems.

An interface mechanism enables the seamless communication and exchange of data between various systems across multiple sites. It ensures separate systems remain connected, providing a single point of truth for clinicians trying to access patient records.

IM1 explained

The IM1 interface mechanism is essentially a set of API standards to support the integration of software or an app with any principal clinical GP system using IM1. Currently, there are three existing suppliers which offer interfaces for systems to integrate with, which include Emis, Vision and SystmOne.

Interface mechanisms enable unrelated systems to do three things:

  1. read patient information
  2. extract patient data in bulk
  3. enter data into other systems

So what does this mean in real terms? What tangible benefits will an interface mechanism deliver to clinicians and patients?

For clinicians, integration will provide them with the support they need to make quicker, more informed clinical decisions relating to a patient’s diagnosis or treatment, and it will also help them manage documentation more efficiently. For patients, integration will give them greater flexibility and control when managing their appointments and prescriptions.

IM1 process

Any consuming supplier can apply to ‘pair’ their service with any provider supplier system, but there are a number of prerequisites set out by NHS Digital that they must meet in order to be deemed compatible.

The compatibility of your product’s application will be assessed against the provider suppliers’ API; you’ll need to include a breakdown of the product you want to develop, and you may be asked to submit evidence to prove you meet the Supplier Conformance Assessment List (SCAL) requirements.

Once your product has been deemed compatible, you’ll be asked to complete a Model Interface Licence with each of the provider suppliers, giving you access to a test environment using the unique provider supplier guidance.

6B partners with your organisation, helping you to develop your product in accordance with the guidance and documentation required for Emis, Vision or SystmOne. We then use machine learning techniques to spot trends and to make autonomous decisions from data insights to uncover more valuable ways of working for your business.

After the assessment phase has been completed, the remaining work is split into the following three stages:

Testing: this phase begins with unsupported testing using the Pairing and Integration Pack (PIP) to iron out any issues that arise, before the process moves onto the supported test environment.

Assurance: once SCAL is agreed with your provider, we can begin to undergo witness testing with your product, where NHS Digital will provide a Recommendation to Connect Notice (RTCN), detailing the plan to connect to IM1.

Live: your product has undergone the necessary testing and assurance checks and it’s now ready to start helping patients. 6B will inform you of the processes you need to follow in order to report faults and incidents, ensuring your product runs as it should.

Integration pairings

In order to join the list of assured suppliers, your product will need to ‘pair’ with one of the following specific APIs for each GP practice system supplier:


  • Patient API: this API allows patients or an authorised representative to book, request, view, amend and cancel appointments or repeat prescriptions, and allows patients to communicate with GP practices directly.
  • Transaction API: with the patient and GP practice system’s permission, this API gives medical professionals access to a whole host of real-time information, ranging from retrieving attachments from a patient’s medical records to creating a new consultation record.
  • Bulk API: once GP practice consent has been obtained, this API empowers your application to gain daily, weekly or monthly extracts of bulk data feeds of patient or clinical system user data.
  • Partner API: similar to the Transaction API, this API offers more up to date information about patients that may have changed since the last query was made e.g. age, sex or the status of an appointment.

Are you a healthcare organisation looking to integrate with IM1?

As an experienced integration partner, 6B works with healthcare organisations of all sizes to ensure their systems can be integrated with clinical systems through an interface mechanism. We’ve worked on NHS web development projects of all sizes and complexities.

At 6B, we think IM1 is the future of interoperability in healthcare. We provide an end-to-end service for organisations who want to integrate their product with clinical systems in the NHS, overseeing everything from identifying and testing a product through to its successful launch.

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