The Mayor of London The London Assembly

2021 Census

The census has been taken every ten years since 1801 (except 1941). It gives us the most comprehensive data on London’s population and is used to inform policy and spending decisions, identify community needs and shape local priorities.

Census day 2021 was Sunday 21 March. 2021 was a ‘digital-first’ census with most people completing it online. A paper questionnaire was also available for anyone who requested it.

Census releases

First population counts from the Census were published on 28 June 2022 with detailed results released from late 2022.

Breakdowns of a single variable including data for small areas were published between November 2022 and January 2023 following this timetable.

Crosstabulations of multiple variables began at the end of March 2023 and continue through spring and summer. 

Release of other census outputs will be phased from September to, at least, the end of 2023. These include migration and travel to work flows, data for ‘small populations’ (which are often localised in specific areas), and data on alternate bases such as workplace or daytime populations. 

Census Information Scheme reports

Reports are published on our census reports page as soon as possible after ONS release data. 

A list of our planned reports is here.

We also produced a report on the first population figures. This should be read alongside our blog post that explains how the census data relates to other population estimates and some of the pitfalls to avoid when interpreting the numbers.

Census Information Scheme 2021

The Census Information Scheme for the 2021 Census came into effect on 1 October 2021. The Scheme provides London-specific analysis of census statistics for the 33 London local authorities, the GLA and its Functional Bodies. Our offer includes:

  • Training and advice about the census and related data sources to both census specialist and wider non-specialist audiences
  • Analysis and reporting of census data including commissioning bespoke outputs and analyses
  • Access to current and previous census data including non-public protected datasets and historic census data for London
  • A voice for London in discussions about the future of census-like statistics