From Open To Controlled: A Five Safes Data Access Spectrum At The Uk Data Service

Access to data is often framed as a binary choice: publish openly or move use into a highly controlled Trusted Research Environment (TRE). In practice, trustworthy digital repositories operate a richer set of options to enhance the responsible use of data. Drawing on the UK Data Service’s three-tier access policy (Open, Safeguarded, and Controlled), we map access conditions onto the Five Safes framework (Safe Data, Safe Projects, Safe People, Safe Settings, and Safe Outputs) to articulate a clearer data access spectrum.

Building on previous work mapping the Five Safes to these three tiers, we extend the approach to four tiers, Open, Safeguarded, Safeguarded+, and Controlled, to make the “middle ground” between open, mostly aggregate data, and TRE-only access more visible. This approach clarifies which additional controls can be layered proportionately (for example, stronger user assurance, enhanced licensing terms, tighter settings, and/or more formal output checks) without defaulting to full TRE workflows.

The result is a practical language and decision aid for data owners and data professionals: it supports consistent governance, improves transparency for researchers, and helps champion access while protecting research participants. Framed this way, the spectrum supports FAIR by making data findable and reusable with clear access terms (not “open by default”) and supports CARE by making explicit the responsibilities and power dynamics around access—who benefits, who is protected, and who decides.