A census has been taken every 10 years since 1801 (except for 1941), but names and personal details were not recorded in the censuses of 1801-1831. The census returns for England and Wales for the period 1841-1901 are now available for inspection at The National Archives, Kew and many local record offices and libraries hold microform copies for their appropriate areas.

The National Library of Wales has microform copies of the census for the whole of Wales and some border areas, 1841-1901.

The census returns from 1841 to 1901 can also be searched and viewed free of charge within the Library through Ancestry Library. Free access is now available to the 1911 census from a dedicated computer within the South Reading Room only.

In addition, some of the returns have been transcribed and indexed by enthusiastic individuals and societies who have generously made them available to the Library's users.