Parliamentary constituencies
The United Kingdom is currently divided into 650 parliamentary constituencies. One Member of Parliament (MP) in the House of Commons represents a single constituency.
Constituency boundaries in the UK have changed. A new set of boundaries for Westminster constituencies was used for the 2024 UK general election.
Why have constituency boundaries changed?
Constituency boundaries are reviewed periodically to make sure that constituencies are all roughly a similar size and respect local ties between areas. The reviews alter constituencies to reflect rising and falling populations and changes in the boundaries of the electoral wards that comprise them.
The four Boundary Commissions for England, Scotland, Wales and Northern Ireland reviewed the UK’s constituency boundaries. They published their final recommendations in June 2023, and the new boundaries they set out were used at the 2024 UK general election.
How much have constituency boundaries changed?
Around 10% of constituencies had no change to their boundaries. The remainder have changed in some way.
In some cases, a ward or several wards moved between constituencies. In others, the changes were more complicated, ranging from small boundary adjustments to constituencies being ‘abolished’ and split between several successor constituencies.
Did my constituency change?
You can find out which constituency you live in, now that the boundaries have changed, by typing your home postcode into the search box at:
You can also see whether, or how, your constituency was affected by the boundary changes using a guide produced by the House of Commons Library before the general election, with maps showing the changes that were being made to each constituency in the UK:
Has the total number of MPs changed?
No. The total number of seats – and so the total number of MPs that were elected at the 2024 general election – did not change. There were still 650 MPs elected in total.
However, the total numbers of seats in England, Scotland and Wales have changed, as follows:
The electorate quota
The electorate quota is the average number of voters each constituency should have if all UK voters were to be distributed evenly between them.
The 2023 boundary review was stricter than previous ones in this respect. Constituencies must now have an electorate within 5% of the ‘electoral quota’ – now set at 73,393 registered voters - with just a few exceptions.
The previous constituency boundaries had been in use in Scotland since 2005 and in the rest of the UK since 2010. The electoral quota was calculated using data from 2000 in England and between 2002 and 2007 in the rest of the UK.
The numbers of voters in former constituencies varied for a number of reasons. These included population change since the previous review and the different rules used before the 2023 review. Previous rules meant different parts of the UK had different electoral quotas and the Boundary Commissions had greater discretion in creating constituencies with electorates further from the quota if they thought local geography or community ties meant it was desirable.
More research from the House of Commons Library: