Written by Technical Team | Last updated 09.01.2026 | 10 minute read
Interoperability has been high on the agenda of the NHS for a while now, and the NHS interoperability strategy details exactly how innovators should approach interoperability. 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, operational efficiency, and population health outcomes.
One of these innovations is IM1 pairing integration. It’s an interface mechanism that enables digital suppliers to talk directly to GP clinical systems (such as EMIS, SystmOne, and Medicus), 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, reducing duplication, minimising errors, and supporting continuity of care across organisational boundaries.
As Integrated Care Systems (ICSs) mature and care delivery becomes increasingly collaborative, mechanisms like IM1 are no longer optional — they are foundational to delivering joined-up, patient-centred care at scale.
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, Medicus and SystmOne.
IM1 was designed to address one of the long-standing challenges within primary care IT: enabling external digital solutions to integrate safely, consistently, and securely with core GP systems without requiring bespoke point-to-point integrations for each practice.
Interface mechanisms enable unrelated systems to do three things:
These capabilities underpin many of the digital services patients and clinicians increasingly rely on, from online appointment booking to remote monitoring, digital triage, and structured clinical data capture.
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. Access to timely, accurate data reduces the risk of missing information and supports safer prescribing, referrals, and follow-ups. Integration also helps clinicians manage documentation more efficiently by reducing duplicate data entry and ensuring records are updated automatically across systems.
For patients, integration will give them greater flexibility and control when managing their appointments and prescriptions. It also improves transparency and trust, as patients can be confident that information shared through digital services is reflected accurately in their GP record.
Why IM1 integration matters: IM1 integration is a core part of the NHS interoperability strategy, enabling secure, real-time data sharing between GP clinical systems and digital health applications. By allowing approved suppliers to read, write, and extract patient data in line with NHS Digital standards, IM1 supports safer clinical decision-making, reduces administrative burden, and improves patient access to GP services. For organisations developing NHS-aligned digital products, IM1 integration is a key enabler of scalable, compliant GP system integration.
IM1 does not exist in isolation. It forms part of a broader ecosystem of NHS interoperability standards aimed at enabling data to flow securely across care settings.
As services move beyond traditional GP-centric models toward multidisciplinary and digitally enabled care, IM1 helps bridge the gap between innovation and core clinical systems. It allows new digital products — such as remote consultation platforms, long-term condition management tools, and patient engagement apps — to integrate directly into day-to-day clinical workflows.
Crucially, IM1 also supports national priorities around:
By standardising how data is accessed and written back to GP systems, IM1 helps ensure innovation can scale safely without compromising governance or data integrity.
When planning a digital health product that connects with GP clinical systems, organisations often face a choice between using the NHS-standard IM1 interface mechanism or building bespoke, practice-by-practice integrations. Understanding the differences helps suppliers make informed decisions about scalability, compliance, and long-term sustainability.
The table below summarises how IM1 compares with traditional bespoke integrations across key considerations that matter most to NHS-aligned digital services.
| Consideration | IM1 Interface Mechanism | Bespoke GP Integrations |
|---|---|---|
| Scalability | Designed to scale nationally across GP systems using a single, standardised approach. | Typically limited to individual practices or regions, requiring repeated builds to scale. |
| Compliance and governance | Aligned with NHS standards, including information governance, clinical safety, and supplier assurance. | Compliance varies by implementation and often requires additional local assurance effort. |
| Implementation effort | Higher upfront assurance and onboarding effort, but reduced complexity once live. | Quicker initial setup in some cases, but increased complexity over time. |
| Ongoing maintenance | Centralised standards reduce ongoing change management and technical debt. | Ongoing updates must be managed separately for each integration. |
| Suitability for NHS-aligned products | Well suited for products intended for widespread NHS adoption and long-term use. | More appropriate for short-term or highly localised solutions. |
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 detailed breakdown of the product you want to develop, outlining its intended functionality, data flows, and clinical safety considerations. You may also be asked to submit evidence to prove you meet the Supplier Conformance Assessment List (SCAL) requirements.
SCAL plays a critical role in ensuring patient safety, data security, and technical reliability. It covers areas such as information governance, clinical risk management, resilience, and adherence to NHS data standards.
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, Medicus 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.
This combination of technical expertise and data-driven insight ensures your product not only meets compliance requirements, but also delivers meaningful outcomes for clinicians, commissioners, and patients.
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. This allows suppliers to validate data flows, error handling, and system behaviour before progressing to the supported test environment, where provider suppliers can offer direct assistance and feedback.
Assurance:
Once SCAL is agreed with your provider, witness testing can begin. During this stage, NHS Digital assesses whether the solution behaves as expected in real-world scenarios. A successful outcome results in a Recommendation to Connect Notice (RTCN), which formally authorises the solution to connect to IM1.
Live:
Your product has undergone the necessary testing and assurance checks and is 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 and remains compliant throughout its lifecycle.
In order to join the list of assured suppliers, your product will need to ‘pair’ with one or more of the following specific APIs for each GP practice system supplier:
Security and governance are central to IM1’s design. All integrations must comply with NHS information governance standards, including data minimisation, role-based access, audit logging, and secure authentication.
Patient consent remains a critical factor. Whether data is accessed in real time or extracted in bulk, clear permissions must be in place, ensuring transparency and maintaining public trust in digital health services.
As the NHS continues its digital transformation journey, IM1 is expected to evolve alongside emerging standards and technologies. Future developments may include greater alignment with FHIR-based APIs, enhanced support for cross-sector data sharing, and tighter integration with national platforms.
For digital suppliers, investing in IM1 integration is not just about compliance — it’s about positioning products to thrive in a healthcare system that increasingly depends on interoperability to deliver safe, efficient, and personalised care.
Is NHS IM1 mandatory for all GP system integrations?
No, IM1 is not legally mandatory, but it is the preferred and recommended route for integrating third-party digital services with GP clinical systems at scale. Many GP system suppliers and NHS organisations strongly favour IM1-compliant solutions because they align with national interoperability, governance, and assurance standards.
How long does it typically take to achieve IM1 approval?
The timeline varies depending on product complexity, readiness, and supplier experience, but achieving IM1 approval commonly takes several months. Time is required for assurance activities such as clinical safety documentation, information governance checks, testing, and witness assessments before a solution can go live.
Can IM1 be used for both patient-facing and clinician-facing applications?
Yes, IM1 supports a wide range of use cases, including patient-facing apps and clinician-facing tools. The specific APIs used depend on the service design, permissions granted, and whether the application is intended to support patient access, clinical workflows, analytics, or a combination of these.
Does IM1 allow access to free text and documents in GP records?
Access to free text and documents is controlled and limited to specific, approved use cases. IM1 prioritises structured data and governed access to records to maintain patient safety, data quality, and confidentiality, meaning not all record content is automatically available to consuming applications.
Is IM1 suitable for pilot projects or proof-of-concept services?
IM1 is primarily designed for production-ready services intended for wider rollout rather than short-term pilots. While it can support pilots, the assurance and onboarding effort means it is usually best suited to solutions with a clear long-term deployment plan within the NHS.
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