Why the census still matters: 200 years of data and what comes next
24 September 2026
Every ten years, millions of us answer questions about ourselves, our households and our lives. Then, for most of us, the census is quickly forgotten. But that seemingly ordinary form creates one of the UK's most valuable sources of information about society.
In the latest episode of Connecting Society, host Mark Green is joined by Jennet Woolford, Director of Social, Local and Census Statistics at the Office for National Statistics (ONS), to explore the history, value and future of the census.
From a headcount to a national resource
The first census of England and Wales took place in 1801, when Parliament needed to understand the size of the population amid the pressures of the Napoleonic Wars and poor harvests.
What began as a basic headcount has evolved into a detailed picture of how we live. Unlike a survey, the census aims to capture everyone, allowing it to provide detailed information about small geographical areas and population groups that surveys may struggle to reach.
It also provides a remarkable record of how society has changed. In 1801, the population of England and Wales was just under nine million – roughly the same as the population of London alone in 2021.
The value of linking data
The census can also provide value long after it has been collected.
During the COVID-19 pandemic, the 2011 census was still being used to understand local populations almost a decade later. ONS also linked census data with COVID-19 infection and vaccination data, helping researchers explore differences between groups and places.
This is where the census increasingly intersects with administrative data. Linking datasets can provide information that would be difficult, expensive or intrusive to collect through the census itself.
For example, ONS used Valuation Office Agency data to provide information about the number of rooms in households, meaning this no longer needed to be collected through the 2021 census.
And this isn't a new idea. In the 19th century, statistician William Farr linked death registrations with census information to explore differences in mortality between occupations.
And then there are the surprises...
The census doesn't just tell us about population numbers and public services. Sometimes, it reveals something unexpected about society.
In 2001, almost 400,000 people recorded their religion as Jedi. Although Jedi wasn't recognised as an official religion, ONS eventually published the figure as an interesting reflection of society.
What comes next?
With the 2031 census confirmed, ONS is now considering what information it should collect. A recent consultation received 730 responses, totalling around 1.6 million words.
The challenge is finding the right balance: collecting information society needs while making the best use of existing administrative data and keeping the census manageable for the public.
For Jennet, the future isn't necessarily about choosing between the census and administrative data. Instead, bringing different sources together could provide richer, more timely insights while preserving the unique information that only a census can capture.
Listen to the full episode now
Listen to the latest episode of Connecting Society to hear more about the surprising history of the census, how its data is used and what its future could look like.
