Importing reference data into the NHS England Secure Data Environment (SDE)

An introduction to the Import reference data service offered by the NHS England Secure Data Environment (SDE).

This service allows researchers to import reference data into the SDE environment for use alongside data sets already available to the user under their Data Sharing Agreement (DSA).

What we mean by reference data

Reference data helps classify, sort or interpret other data. It is usually static or changes slowly over time.

This service does not allow for the import of any personal or confidential data. To meet this type of user need, view our overview of our Import research data service.

How this service works

Users prepare their file according to our detailed guidance. Once the file is ready, the user raises a request, uploading the file into the portal.

We check the submitted files using automated and manual checks.

We aim to complete checks within 5 working days. Some requests may be completed sooner.

Further information

To learn how to get access to the NHS England SDE, visit our process overview which explains how to get started with understanding what data is available and how to start an application.

Access the user guidance page for detailed information on how to prepare your file and then raise and track your request.

Last edited: 7 July 2026 8:43 am