A census is a count of all people and households in the country. It provides population statistics from a national to neighbourhood level for government, local authorities, business and communities.

Since 1801, every ten years the nation has set aside one day for the census - a count of all people and households. It is the most complete source of information about the population that we have.

Every effort is made to include everyone, and that is why the census is so important. It is the only survey which provides a detailed picture of the entire population, and is unique because it covers everyone at the same time and asks the same core questions everywhere. This makes it easy to compare different parts of the country.

The information the census provides allows central and local government, health authorities and many other organisations to target their resources more effectively and to plan housing, education, health and transport services for years to come.

In England and Wales, the census is planned and carried out by the Office for National Statistics. Elsewhere in the UK, responsibility lies with the General Register Office for Scotland and the Northern Ireland Statistics and Research Agency.

The last census for England and Wales was on 29 April 2001. The next will take place on 27 March 2011 and will involve around 25 million households. This census will be the first one where returns can be made electronically.