UK Census returns of 1801 - 1831

England, Scotland and Wales actually did census work before 1841. I discovered the following discussion on the web:

The UK Census was taken every 10 years from 1801, except in the war year of 1941. Only those from 1841 to 1901 are generally available.

The 1801 census asked local officials to provide information on the number of inhabited and uninhabited houses in the parish and how many families occupied them; the number of people in the parish and their employment; and numbers of baptisms, burials and marriages in the previous 100 years. A similar format was followed for the censuses of 1811, 1821 and 1831, with the addition of further questions. In 1811, the enumerators were asked to give more information about the reasons houses were unoccupied, so that the prosperity of the district could be more accurately gauged. In 1821 a question relating to age was asked, in order to assess numbers of men able to bear arms, and to improve the tables on which life assurance was based. More detailed questions on occupations from 1831 provided the government with economic information.

Most of the early returns for 1801-1831 were destroyed, only statistical summeries being published. Those few returns that survive are now usually in the local County Record Office. The returns usually only name the householder and list the number of people in the house, although occasionally the whole population is listed.

These are the census dates for England & Wales including the later ones are:

1801 March 10th
1811 May 27th
1821 May 28th
1831 May 30th
1841 June 6th
1851 March 30th
1861 April 7th
1871 April 2nd
1881 April 3rd
1891 April 5th
1901 March 31st
1911 April 2nd
1921 June 19th