The Office for National Statistics in England and Wales and the General Register Office in Scotland are responsible for the collection of census data.
Scotland's census is organised by the National Records of Scotland (NRS).
In the UK, a census is taken on a single day, usually the third Sunday of April, once every ten years. Everyone, by law, must take part. All households in the UK will receive a census form and must complete it with information about everyone living in the household.
Information asked about each individual includes:
Other information collected includes:
Once the results are collected, they are analysed.
Events such as births, marriages and deaths must be registered by law in the UK. This means data that was collected in a census can be updated and changes can be monitored.
This data is used by the government to make plans for maternity care, education, pensions, employment, housing and transport. The government need to know about changes in population so they can make plans for the use of their resources, for example, do they need more schools?
In some countries, the data is used to inform population policies. For example, when the Chinese government wanted to control population growth they brought in the one-child policy to reduce the birth rate.