The CHAIN reports on the London Datastore present information about people seen rough sleeping by outreach teams in London since 2009/10. Information in the reports are taken from the Combined Homelessness and Information Network (CHAIN), a multi-agency database recording information about rough sleepers and the wider street population in London. CHAIN is commissioned and funded by the Greater London Authority (GLA) and managed by St Mungo’s, and represents the UK’s most detailed and comprehensive source of information about rough sleeping.

Services that record information on CHAIN include outreach teams, accommodation projects, day centres and specialist projects such as the GLA-commissioned No Second Night Out. The system allows users to share information about work done with rough sleepers and about their needs, ensuring that they receive the most appropriate support and that efforts are not duplicated.

In these reports, people are counted as having been seen sleeping rough if they have been encountered by a commissioned outreach worker bedded down on the street, or in other open spaces or locations not designed for habitation, such as doorways, stairwells, parks or derelict buildings. The report does not include “hidden homeless” groups such as people “sofa surfing” or living in squats, unless they have also been seen bedded down in one of the settings outlined above.

Separate reports are produced for London as a whole and for individual boroughs, and these are published each quarter. There are also annual reports that contain aggregated information for all four quarters of the year. The reports available on the Datastore cover the period from 1 April 2014 onwards, while earlier reports can be found on the St Mungo’s website.