Help and guidance

Contact our helpdesk to submit a query and guidance relating to the content of the NHS Data Model and Dictionary.


The NHS Data Model and Dictionary is modelled using the following convention and naming:

  • Data Sets are built from a series of Data Elements and, optionally, groups of data elements.
  • Data Elements are a specialised use of Attributes for use within the context of the data set. For example they may introduce default codes applicable to a specific data element, perhaps to handle circumstances where data are not available.
  • Attributes describe the properties of Classes and provide common data definitions for classes. A class may in turn be a specialised form of another class (a subtype).
  • Classes describe aspects of the health and care business with their significant characteristics through their Attributes and their relationships to other Classes.
  • NHS Business Definitions describe specific applications of Classes within the context of the health and care system but don't introduce new attributes or relationships.
  • Supporting Information is not a part of the NHS Data Model but provides additional context for the reader.
  • XML Schema Constraints provide details of restrictions on the data permitted in XML schema for data sets.
  • Retired items are not included in the current definitions but are listed in the All Items Index.

Frequently Asked Questions

Published Information Standards

Archive of Data Set Change Notices (DSCNs) published prior to 2020

Keeping you informed

The NHS Data Model and Dictionary Service operates a Mailing List service, which is specifically designed to make users aware of changes to their products, such as:

  • New NHS Data Model and Dictionary releases;
  • Proposed changes to the NHS Data Model and Dictionary.

To subscribe to the mailing list, please send an email to, with 'NHS Data Model and Dictionary Mailing List' in the subject field.

Contact Us

If you would like to ask a question or make a suggestion about any aspect of the NHS Data Model and Dictionary please email

The subject of your email should read 'NHS Data Model and Dictionary Query'. Please include your:

  • Full name
  • Job title
  • Telephone number
  • Organisation
  • A full description of your query with a suggested resolution.

You should expect to receive a response within 6 working days from the day when your request was originally received by the NHS Data Model and Dictionary Service.

After receiving a response you will be asked to complete a customer satisfaction survey, this is your opportunity to rate the quality of our NHS Data Model and Dictionary Service and the quality of the response you received.