Welcome to UK LLC Guidebook

Last modified: 22 Oct 2026

The go-to resource for researchers wanting to access, understand and work securely with data in the UK LLC TRE.

UK LLC is the national Trusted Research Environment (TRE) for data linkage in longitudinal research, bringing together data from Longitudinal Population Studies (LPS) and linking these to study participants’ health, administrative and place-based records (where participant permissions allow). As summarised in the diagram below, UK LLC is committed to four nations coverage, is free to access and researchers can currently request access to LPS participants’ records linked to NHS England and geographic datasets (where participant permissions allow). Click on the links below to read more about:

• Available linkages - see which LPS are already linked to their participants’ health records and geographic datasets

• UK LLC’s unique attributes - why you should consider UK LLC for your next research project

• UK LLC’s ongoing development - expansion in partner LPS and data sources, and synthetic data and training TRE

• UK LLC’s published protocol - explains in detail how UK LLC works.

If you are not a researcher, you may find this guide helpful: Where to find the information you need.