The 2001 census was carried out for the population of the United Kingdom, allowing the government to discern the number of people under their protection and the people of the country to determine their number of fellow citizens. As such, the Census 2001 proceedings were marked as the 20th such procedure to be administered in the country. The 2001 Census records were collected on April 29 of that year, a Sunday, and more specifically in the evening. The 2001 Census indicated that the U.K. population at that time was 58,789,194.
Administrative purview of the Census 2001 efforts was divvied up according to the specific dominion of the United Kingdom under consideration. In this respect, the Office for National Statistics, also known as the ONS, handled the distribution and, then, collection of Census 2001 forms for the areas of Wales and England.
Up in Scotland, meanwhile, the 2001 census was carried out by GROS, or the General Register Office for Scotland. Over in Northern Ireland, moreover, Census 2001 responsibilities were tasked to the offices of the Northern Ireland Statistics and Research Agency, also known by the acronym NISRA.
According to estimates thereafter issued by Census 2001 sources, up to 6% of the English and Welsh populations were excluded, by choice or circumstance, from the 2001 Census. In Northern Ireland, the lower figure of 4.8% was believed to have slipped through the 2001 census net, and just 2.9% were believed to have been unaccounted for in Scotland, with the most undercounted individual area being Hackney.