The Unified UK Census Dataset (2021/2022) is a harmonised, small-area dataset that brings together census data from
the three UK census agencies -- ONS (England & Wales), NRS (Scotland), and NISRA (Northern Ireland) -- into a single,
comparable release. The UK's census agencies each publish their data separately, with distinct variables, question
wordings, formats, and disclosure controls. Through a process of manual variable matching, standardisation, and
aggregation, 190 comparable variables are produced across 25 topic tables for Output Areas (OAs) in England, Wales,
and Scotland, and Data Zones (DZs) in Northern Ireland, comprising 239,023 small areas across the United Kingdom.
Please see the accompanying paper below for comprehensive documentation of the harmonisation methodology and data
sources. The tables span demographics, ethnicity, health, housing, and employment.
Content
The dataset available for download contains the counts for all 190 variables plus 25 table totals (215
variables in total) across each of the 239,023 small-area geographies.
Data Zones are relabelled as "OA" in the dataset for consistency. Both CSV and Apache Parquet formats are provided.
For a detailed description of all variables contained within the data, see the Variable Metadata file; and for notes
on harmonisation decisions and cross-national differences for each table, see the Table Notes file. These files can be
downloaded alongside the topic tables.
Quality, Representation and Bias
The data are compiled from the official census releases of the three UK statistical agencies, each of which applies
its own disclosure control and data quality procedures. The census data represent a near-complete enumeration of the
usually resident population on Census Day: 21 March 2021 for England, Wales, and Northern Ireland, and 20 March 2022
for Scotland.
Users should note that:
- The Scottish census was conducted one year later than the rest of the UK (2022 vs 2021), which may introduce
temporal differences in some variables.
- The COVID-19 pandemic severely impacted method of travel to workplace data across all nations.
- Variable definitions are not always directly equivalent across countries. For example, Scotland's qualification
levels reflect a different education system. The Table Notes document these differences in detail.
