Sources for genealogical research in London are categorised into those relating to national records, and those concerning mainly, but not solely, London, Middlesex, Metropolitan Surrey and Kent. A service is also offered with regard to the county of Essex

• The National Archives
- military service records
- merchant marine
- metropolitan police
- immigration
- criminals and criminal proceedings

• British Library & India Office
- printed works
- India Office

• Newspaper Library
- national and local newspaper editions 18th century to date

• Principal Probate Registry
- wills and administrations 1858 to date

• London Metropolitan Archives
- Middlesex, County of London, Metropolitan Surrey & Kent

• The Guildhall Library
- City of London

• Westminster Archives
- City of Westminster

• Society of Genealogists
- extensive collections relating to all areas and periods

• Essex Record Office
- all records relating to the county of Essex