Accessing data via public data repositories

The vast majority of CLS research data are publicly available through the UK Data Service, although there are a few specialised data available in other public data repositories.

UK Data Service

The UK Data Service is a national digital repository and data sharing platform for social and health research data, based at the University of Essex. The following links will take you to the relevant area of the UK Data Service for each of our four studies:

Access to data held by the UK Data Service varies depending on how we have de-identified and classified the data (CLS Data Classification Policy):

  • Safeguarded data (Tier 1a): data with a low level of sensitivity and disclosivity, available under the UKDS End User Licence (EUL). Your application is authorised directly by the UK Data Service, and you can download the data directly from there.
  • Special safeguarded data (Tier 1b): data with a moderate level of sensitive or disclosivity, available under the UKDS Special Licence (SL). You will need to apply for access through the UK Data Service and your application needs to be approved by CLS before you can download the data.
  • Controlled data (Tier 2): highly sensitive and/or potentially disclosive data, available from the UKDS SecureLab under Secure Access Licence (SA). You will need to apply for access through the UK Data Service and attend a specialised training course. Your application needs to then be approved by CLS before you can download the data. You can only access these data via a UK Data Service SecureLab account.

You can find more information about the different types of data access at the UKDS on their webpages.

The UK Data Service is a member of the International Data Access Network (IDAN). As such, CLS controlled data can be accessed from Safe Room access points at GESIS, Leibniz-Institute for the Social Sciences (Cologne/ Mannheim) in Germany. You can visit the UKDS website to learn more about IDAN and accessing controlled CLS data from Germany.

Other public repositories

  • Welsh administrative data linked to the Millennium Cohort Study can be remotely accessed via the SAIL Databank. These data are Tier 2b.
  • CLS data linked to NHS data can be accessed via the UK Longitudinal Linkage Collaboration (UK LLC).
  • NCDS genetic data (not linked to survey data) are available for researchers to download from the European Genome-Phenome Archive (EGA). Access requires an application to the Wellcome Trust Sanger Data Access Committee at These data are Tier 2a.

To access CLS research data not available via these routes, including biological samples and genetic data linked to survey data, you need to apply directly to CLS.

For proposals to generate new linked data, new data collections, or enrichment of legacy data, please visit: Proposing data linkages and enhancements.

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL


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