FHIR UK Core: What You Need To Know

If you’ve been anywhere near the world of digital health in the UK, you’ll know that everyone seems to be talking about FHIR. Whether it’s the NHS App, GP Connect, or shared care records across Integrated Care Systems (ICSs), FHIR (Fast Healthcare Interoperability Resources) has become the go-to standard for moving health data between systems.

But here’s where things get interesting: when we say “FHIR” in the context of UK healthcare, we’re not just talking about the international HL7 FHIR standard. We’re actually talking about something called FHIR UK Core.

Now, if that phrase sounds a bit technical, don’t worry. By the time we’re done here, you’ll understand exactly what FHIR UK Core is, why it matters for the NHS, how it relates to openEHR and information governance, and what it looks like in practice.

First, a Quick Recap: What is FHIR?

Let’s start at the beginning. FHIR (Fast Healthcare Interoperability Resources) is an international standard developed by HL7 International. The idea is simple: create a common “language” so healthcare systems can talk to each other.

Instead of one hospital storing blood pressure as “BP” and another calling it “Systolic/Diastolic Reading,” FHIR gives everyone a standard way to represent that information. It does this through resources—building blocks like:

• Patient (basic demographics)
• Observation (lab results, vital signs)
• MedicationRequest (prescriptions)
• Condition (diagnoses)

On top of that, FHIR uses modern web technologies like REST APIs, JSON, and XML, so developers can work with healthcare data the same way they work with any other web data.

Sounds great, right? But there’s a problem. The international FHIR standard is broad by design—it has to cover everything from US hospitals to European research labs to Australian GPs. That flexibility is a blessing and a curse. It means lots of optional fields, lots of possible variations, and sometimes confusion when two systems both say they’re “FHIR compliant” but can’t actually understand each other’s data.

Enter FHIR UK Core

This is where FHIR UK Core comes in. Think of it as the UK’s customised version of FHIR, built to meet the specific needs of the NHS and UK healthcare providers.

In other words, FHIR UK Core takes the international standard and narrows it down. It defines which fields are mandatory, which ones are optional, and how data should be represented in a UK context. It’s about making sure that when one NHS system sends data and another receives it, both sides know exactly what to expect.

For example:

• In the UK, we use NHS Numbers as patient identifiers. FHIR UK Core specifies how that should be represented in the Patient resource.
• For addresses, it aligns with UK postal standards.
• For medications, it ties into SNOMED CT UK Edition and dm+d (Dictionary of Medicines and Devices).
• For conditions, it makes sure everything maps correctly to UK-specific terminologies.

So, FHIR UK Core is basically the UK’s official implementation guide for FHIR. It ensures that digital health solutions work consistently across the NHS, regardless of vendor or region.

Why Does FHIR UK Core Matter for the NHS?

Let’s be real—interoperability in the NHS has been a challenge for decades. Different Trusts run different EHR systems, GP practices use suppliers like EMIS or TPP, and community and mental health services often have their own software too. Add to that the growing world of patient apps, wearable devices, and research platforms, and you’ve got a recipe for fragmentation.

FHIR UK Core is about solving that. It gives everyone a baseline standard. If you’re building an API, a patient app, or even a whole EHR, using FHIR UK Core means your system can “speak NHS.”

Some real-world examples include:

• NHS App: When you view your GP record or order repeat prescriptions, FHIR APIs (based on UK Core) are working in the background.
• GP Connect: Allows clinicians to access GP records across practices, again built on FHIR UK Core standards.
• Shared Care Records (ICSs): Integrated Care Systems use FHIR UK Core to exchange patient data across hospitals, GPs, and social care.

Without UK Core, every system would implement FHIR slightly differently, and we’d end up back at square one: data silos.

FHIR UK Core vs. openEHR

You might have also heard about openEHR, especially in discussions about clinical data repositories. So how does that fit in with FHIR UK Core?

Here’s the simple breakdown:

• FHIR UK Core = data exchange standard (how systems talk to each other).
• openEHR = data storage standard (how you build long-term, vendor-neutral clinical data repositories).

So, a Trust might use openEHR to store a patient’s complete record internally, then use FHIR UK Core APIs to share parts of that record with another hospital or with the NHS App. They’re not competitors—they’re complementary.

How FHIR UK Core Supports Information Governance

We can’t talk about UK healthcare data without talking about information governance. Because FHIR UK Core isn’t just about interoperability—it also helps ensure safe, lawful, and accountable data sharing.

Here’s how:

• Standardised identifiers: By defining how to use NHS Numbers in the Patient resource, FHIR UK Core reduces the risk of mismatching patients.
• Consistent coding systems: By aligning with SNOMED CT and dm+d, it ensures clinical data is safe, precise, and unambiguous.
• Secure APIs: Most FHIR UK Core implementations in the NHS require OAuth2.0 and NHS Login, ensuring only the right people (or patients) can access sensitive information.
• Auditability: Because the APIs are standardised, it’s easier to log and audit every access or transaction.

So in practice, FHIR UK Core doesn’t just connect systems—it makes sure those connections meet the governance expectations of the NHS.

Challenges of Implementing FHIR UK Core

Of course, adopting FHIR UK Core isn’t as simple as flipping a switch. There are some challenges:

• Legacy systems: Many NHS systems are decades old and weren’t designed for FHIR APIs. Retrofitting them to support UK Core can be complex and costly.
• Supplier readiness: Some vendors are more advanced than others in adopting UK Core. Getting everyone aligned takes time.
• Data quality: If the underlying data is incomplete or inconsistent, exposing it via FHIR APIs won’t magically fix the problem.
• Complexity of standards: For smaller digital health startups, learning and implementing UK Core can be daunting.
• Ongoing evolution: UK Core is constantly being updated to reflect new use cases, so systems have to adapt.

But these are growing pains, not deal breakers. Over time, as more NHS projects adopt UK Core, the ecosystem will get stronger and more consistent.

Benefits of FHIR UK Core

Let’s focus on the positives, because the benefits are huge:

• True interoperability: Systems across the NHS can finally share data in a consistent way.
• Patient empowerment: With APIs based on UK Core, patients can safely access their own data through the NHS App or other approved apps.
• Innovation: Startups and digital health companies can build apps that plug into NHS systems without reinventing the wheel.
• Better clinical decision-making: Clinicians get more complete, standardised information at the point of care.
• National scalability: Because it’s a single national standard, projects can scale across the UK instead of being limited to local pilots.

What the Future Looks Like

Looking ahead, it’s hard to imagine a connected NHS without FHIR UK Core at its heart. As the NHS continues its push for interoperability, UK Core will underpin:

• Expanded NHS App features (access to more parts of the patient record).
• Shared Care Records across all Integrated Care Systems.
• Integration with wearables and remote monitoring (think blood pressure cuffs or glucose sensors feeding data back into GP records).
• AI and analytics: With structured, consistent data flowing through APIs, the NHS can finally unlock the full potential of artificial intelligence in healthcare.

And let’s not forget research. Properly governed FHIR UK Core data flows will power population health studies, clinical trials, and even pharmaceutical innovation—all without compromising patient privacy.

Final Thoughts

So, if someone asks you “what’s FHIR UK Core and why should I care?”, here’s the simple answer:

It’s the UK’s official version of FHIR, tailored for NHS needs. It ensures that whether you’re a GP practice, a hospital, a digital health startup, or the NHS App, you’re all speaking the same data language. Without it, interoperability in UK healthcare would remain a dream. With it, we’re finally building the connected, patient-centred NHS everyone’s been talking about for years.

FHIR gives us the pipes. FHIR UK Core makes sure those pipes connect properly in the NHS context. And that’s why it’s such a big deal.