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The NHS Digital Terminology Server

A terminology solution to help healthcare IT systems speak the same language, and make mapping codes between organisations faster and easier.


What is a terminology server?

Healthcare organisations often use different software and different words, or 'terminologies', to record health information: what one doctor records in their system as a 'chest infection', for example, might be recorded as 'upper-respiratory infection' in another, so the two systems might not be able to match the information up.

A terminology server transforms the way in which data is captured, shared and analysed across health and care, meaning more effective, efficient and safer decision-making. This makes providing healthcare services, treatment and cures more efficient and cost-effective.

It also makes it possible to load local codes and map these to national codes, or other local or system codes.

The NHS Digital Terminology Server

The NHS Digital Terminology Server is a FHIR® compliant solution that holds and disseminates assured international terminologies and classifications (such as SNOMED-CT and ICD-10) and national terminologies (such as NHS Data Model and Dictionary codes).

We have developed the NHS Digital Terminology Server to deliver assured content in FHIR® compliant, machine readable formats – regardless of which terminology is being accessed. The accuracy of the content is maintained through tightly managed editorial controls. This will remove the need to manually update your systems with downloaded content from TRUD and other terminology sites.

There is also a syndication feed (API) which enables content to be syndicated across a group of terminology servers. This allows you to share your own terminologies with others.

Content included in the Terminology Server

Code systems, value sets and concept maps for a growing number of national and internationally assured terminologies and classifications are included in the NHS Digital Terminology Server.

Currently loaded are:

We plan to load:

  • Data dictionary - including all reference data national codes and historical versions
  • dm+d - including historical versions

Complex mapping tables between the currently loaded code systems are NOT currently available via the Terminology Server.  

For details of mapping tables, please contact the individual teams by following the links above.

Who can use it

Potential users who will benefit from using the NHS Digital terminology server include:

  • providers of health and care services
  • commissioners of health and care services
  • population health managers
  • suppliers in the health and care market
  • researchers and analysts

Access to some of the content within the NHS Digital Terminology Server will be freely available for read access (such as Data Dictionary). Other content will be subject to access controls appropriate to the licensed content (such as SNOMED CT).

The various environments

There are several different FHIR servers that make up the Terminology Server.  

Find out more in the NHS Digital Terminology Server environments webpage.

How to get access

Individual users can access content on the NHS Digital Terminology Server with a registered account (authenticated) or without a registered account (non-authenticated).

Guidance for how to register for an account as an individual is provided in our account management guide.

Details of the current status of the Terminology Server and links to tools for interacting with the terminology server and its API endpoints can be found on our Service Navigation and Status page.

If you wish to access the Terminology Server from a software application or to syndicate content to your own terminology server, rather than access via a browser, you will need a system-to-system account. Please complete a system to system account request form.

How to integrate your system

See the guidance for software developers interested in integrating their system with NHS Digital's Terminology Server.

Training material

How to buy your own terminology server

You may want to buy your own terminology server, to manage and create content yourself and share it with other terminology servers, including the NHS Digital Terminology Server.

We have set up a framework agreement with Dedalus which might help.

Quick start for beginners

What is FHIR®?

The Terminology Server stores information in the HL7 FHIR® (Fast Healthcare Interoperability Resources) standard.

Read more about it at       

More information about how NHS Digital use FHIR® can be found in the NHS Digital FHIR® API website.

How to add content

Adding content to the Terminology Server can be done using the Snapper:Author web tool.

Find training on how to use Snapper.

Quick start for developers

How to use your credentials

Please see the following link for some further information about the supported operations and examples of how to use the system-to-system credentials to get a token and make an API request:

Using account credentials

How to use FHIR®

The terminology server is FHIR R4 compliant and the API parameters and operations are as specified in the FHIR R4 standard:

The key Resources you will likely be interested in are 

Code system
Value set
Concept map

Where the standard indicates implementation discretion you will find more specifics here: Ontoserver – (

Example interactions

This postman collection contains examples that you may find helpful in understanding the basics of the interactions.
To run the examples against the Terminology Server you’ll need to replace the root url in the examples with the Production Server equivalent.

If the content you are trying to access requires authentication then you will also need to pass the Authorisation Header as described in “Example of using a token” on Using account credentials.

Using the environments

An explanation of the various environments is provided here: NHS Digital Terminology Server environments - NHS Digital

To use/consume existing content for exploration and analysis then you should use Production 1.

Testing should also be carried out on Production 1.

The Authoring Server is restricted for the internal validation and release of national code systems.  If you feel you need to use the Authoring Server specifically then please explain the need

For runtime use in a clinical system there is a dedicated Production Server (Production 2) but you will need to explain your intended use in order to gain access.

Contact us for system support

In-hours support

Monday to Friday 9am to 5pm excluding English bank holidays:

Out of hours support

High Severity Service Incidents (such as, the system is unavailable or there has been a security breach):

Non-High Severity Service Incidents (your incident ticket will be reviewed the following working day):


Last edited: 22 October 2021 2:50 pm