Electoral statistics, UK: 2019

• The total number of UK Parliamentary electoral registrations increased by 1,299,100 (2.8%) between December 2018 and December 2019, compared with a decrease of 0.8% in the previous year.

• The number of Parliamentary and local government electoral registrations increased across all four countries of the UK.

• In December 2019, there were 47,074,800 Parliamentary electoral registrations and 49,153,700 local government electoral registrations.

• Electoral registrations increased in 609 of the 650 UK Parliamentary constituencies, with the largest increases often in areas with large student populations.

• Cardiff Central in Wales had the highest growth in the number of Parliamentary electors in the year to December 2019 while Scunthorpe in Yorkshire and The Humber saw the largest decrease.

Statistician's comment

"The number of electoral registrations in December 2019 was the highest ever seen, surpassing the previous peak of December 2012. The rise is partly a reflection of a busy year of elections with local government, mayoral and European elections, and a rise in the number of eligible voters between 2018 and 2019. Of course it culminated in the December 2019 General Election, the first in that month since 1923, and captures the uplift in electoral registrations that is to be expected."

Neil Park, Centre for Ageing and Demography, Office for National Statistics

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The total number of UK Parliamentary electoral registrations in December 2019 was 47,074,800, an increase of 1,299,100 (2.8%) from the previous year.

Figure 1 shows the number of Parliamentary electoral registrations from December 1991 to December 2019. The number of electoral registrations is at its highest level, surpassing the previous peak in December 2012.

The increase between December 2018 and December 2019 is likely to reflect a number of contributory factors. Some of the 1,299,100 increase is probably because of an increase in the number of people aged 18 years and over in the population (increasing from 52.4 million to 52.7 million, or by 289,000, between mid-2018 and mid-2019). However, some of the increase in the population aged 18 years and over will include residents who are ineligible to vote (see Measuring the data for more information on eligibility). Further information on the population of people aged 18 years and over can be found in the mid-year population estimates.

Additionally, a busy year of elections across the UK with local, mayoral and European elections in May and the general election in December are likely to have increased interest in politics and resulted in an uplift of electoral registrations. Further, the close correspondence between the reference date for Electoral statistics (1 December) and the general election (12 December) mean that the electoral statistics presented here reflect most of the increase in electoral registrations immediately before the December election.

An increase in electoral registrations is a feature often seen in the lead-up to general elections. Figure 2 shows the number of Parliamentary electoral registrations for the last five years for the usual 1 December reference point, UK general elections and the 2016 EU referendum. The number of registrations are highest at the election points and, with the exception of 1 December 2019, lower at the 1 December reference points. For example, the number of electoral registrations at 1 December 2016 was 709,000 lower than at the June 2016 EU referendum and 1,069,000 lower than at the May 2017 General Election.

As shown by Figure 2, the number of electoral registrations is usually highest around the time of general elections. This year's Electoral statistics release is unusual as the high of level of registrations at the time of the election coincides with our regular collection of electoral statistics.

Usually the electoral statistics reflect the number of electoral registrations following the annual canvass. The annual canvass helps ensure the accuracy and completeness of the electoral register by helping to identify those who should be registered but are currently not, as well as identifying electors who are no longer at a property and should therefore be removed from the register. In this year's Electoral statistics we are comparing December 2019, a peak level of electoral registrations associated with an election, against the more usual post-annual canvass levels.

More information on the coherence between the size of the electorate at the time of the December 2019 General Election and the number of electoral registrations presented in this bulletin can be found in Section 8.

Figure 3 shows the change in the number of Parliamentary electoral registrations for UK constituent countries over the last two years. All four countries across the UK had an increase in Parliamentary electoral registrations in the year to December 2019. Wales and Northern Ireland both had the greatest percentage increase (3.8%) and the lowest increase was Scotland with 1.6%.

The datasets published alongside this bulletin provide the number of electoral registrations in the latest and previous year for each Westminster Parliamentary constituency. Figure 4 shows the 10 areas that experienced the greatest percentage increases in Parliamentary electoral registrations between December 2018 and December 2019.

In the year to December 2019, the number of Parliamentary electoral registrations increased in 94% (609) of Parliamentary constituencies; in the year to December 2018, 75% (486) of constituencies saw reductions in electoral registrations.

With the exception of Cardiff Central, which had the highest percentage increase, most of the largest increases in Parliamentary electoral registrations were areas in England. All these areas saw a decrease in Parliamentary electors in the year to December 2018. A common feature of many of these areas is they have large populations of students and a high level of population churn; new cohorts of students arrive every year and graduates leave.

Figure 5 shows Parliamentary constituencies with the largest percentage decreases in electoral registrations in the year to December 2019. These were spread across the UK. The largest decrease was in Scunthorpe in Yorkshire and The Humber.

• Scunthorpe decreased by 4.3% in the year to December 2019 but increased by 3.2% the previous year.

• South Swindon decreased by 3.8% in the year to December 2019 but increased by 2.0% in the year before.

• Brigg and Goole decreased by 3.8% in the year to December 2019 but increased by 2.5% the previous year.

The interactive maps in Figure 6 shows the percentage change in Parliamentary electoral registrations in the last five years across the UK.

Figure 6: Electoral registration increased in most areas in the year to December 2019

Interactive map showing change in Parliamentary electoral registrations across the UK

Data download

In the year to 2019, 94% of Parliamentary constituency areas saw an increase in the number of Parliamentary electoral registrations. Figure 6 shows the change in the number of electoral registrations from year to year. Typically, in years with general elections or national referenda, the number of electoral registrations tends to increase, while in the years following these events the number of electoral registrations often decreases.

The total number of UK local government electoral registrations in December 2019 was 49,153,700, an increase of 2.9% from December 2018.

Overall, the pattern of change across the UK was similar to that of Parliamentary electoral registrations. The total numbers of local government electoral registrations in each of the UK constituent countries and the percentage changes between 2018 and 2019 were:

• England - 41,306,500, an increase of 2.9%
• Wales - 2,349,400, an increase of 3.7%
• Scotland - 4,167,400, an increase of 1.5%
• Northern Ireland - 1,330,500, an increase of 3.8%

With the exception of Northern Ireland, the increase in electoral registrations in the year to December 2019 followed a decrease in the previous year.

The 10 local government areas that experienced the greatest increases in the number of local government electors between 2018 and 2019 are shown in Figure 7. Nine of the local government areas with the greatest percentage increases were in England. A common feature of most of these areas is they have large populations of students and a high level of population churn; new cohorts of students arrive every year and graduates leave.

Figure 8 shows the 10 areas that had the greatest percentage decreases in local government electoral registrations in the year to December 2019. Two of the areas, the Isles of Scilly and City of London both have very small populations (of 2,200 and 9,700 respectively in mid-2019) and annual percentage changes in the number of electoral registrations can be volatile as a result. North Lincolnshire had the largest decrease (4.8%), but this followed an increase in the previous year of 4.3%, the second-largest in the UK.

The total number of overseas electors on the electoral register in December 2019 in England and Wales was 192,500, an increase of 63.8% since December 2018. England had an increase of 63.0% and Wales an increase of 89.5% (Figure 9). The large increase in the number of overseas electors in the year to December 2019 is likely to have been driven by the general election.

The number of electors opting out of the open register in England and Wales in the year to December 2019 was 27,352,400, an increase of 6.4% from the previous year (Figure 10). Further information on opting out of the open register is available.

The number of anonymous electoral registrations in England and Wales increased by 26.1% from 2,700 to 3,400 in the year to December 2019 (Figure 11). The number of anonymous electoral registrations in England has more than doubled since December 2011. Further information on anonymous electors is available (PDF, 112KB).

In the year to December 2019, there were 2,057,900 (non-UK) European citizens on the electoral register for local government elections in England and Wales, or 4.7% of the total number of local government electors. The number of EU citizens on the electoral register in England and Wales increased by 7.6% in the year to December 2019; by 11.1% in Wales and 7.6% in England.

The total number of Parliamentary electoral registrations reported in this release is around half a million lower than in comparable electoral registrations data (XLSX, 379KB) relating to the December 2019 General Election.

The electoral statistics for 2019 included in this bulletin nominally relate to the number of people on the electoral register as at a reference date of 1 December 2019. However, because of the priority given to administering the general election held on 12 December, electoral registration officers (EROs) published their registers at different times throughout November and March. In the absence of an election the range of publication dates by the EROs would have made little difference to the numbers reported. For example, the number of people on the electoral register at the start of December would generally not have changed much from the number in the first half of November.

However, the data for those EROs who published their registers in November 2019 will not include people who subsequently registered to vote in the general election held on 12 December (people had until 26 November to register for a vote in the general election). Including these later voter registrations provided an uplift to the total number of UK Parliamentary electoral registrations across the UK, bringing the total on election day up to 47,567,800. This was 493,000 (1%) higher than the number of electoral registrations at 1 December 2019.

Annual canvass

By law the register of electors is checked each year by sending a household enquiry form to every household in the council area. This is known as the annual canvass. The purpose of the canvass is to identify everyone who should be on the electoral register. This means identifying citizens who should be registered but are currently not, as well as identifying electors who are no longer at a property and should therefore be removed from the register. A revised version of the electoral register must be published by 1 December, following the conclusion of the annual canvass.

Electoral register

The electoral register is a list of all people who are registered to vote in elections and referendums. The creation and maintenance of the electoral register is the responsibility of local electoral registration officers.

Electoral registrations

The number of registrations on the electoral register. It should be noted that individuals who have more than one address may register in more than one place and that not everyone eligible to vote is registered to vote. Additionally, not everyone usually resident in the UK is entitled to vote.

Parliamentary electors

The total number of Parliamentary electors consists of residential qualifiers, attainers and overseas electors. Further information on who can vote in different UK elections can be found on the GOV.UK website.

Local government electors

The total number of local government electors consists of residential qualifiers and attainers, including peers and European Union citizens. Local government areas are unitary authorities, London boroughs and district councils in England; unitary authorities in Wales and council areas in Scotland and Northern Ireland. Further information on who can vote in different UK elections can be found on the GOV.UK website.

Attainer

Attainer is the term used to describe a person who attains the age of 18 years during the normal currency of the register (after 1 December 2019 but before 1 December 2020), and is entitled to vote at an election held on or after his or her 18th birthday. As a result of the "Scottish Elections (Reduction of Voting Age) Bill", which was passed by the Scottish Parliament in 2015, 16- and 17-year-olds are now eligible to vote in local government elections in Scotland. Attainers, are therefore those who will reach the age of 16 years during the currency of the register.

Overseas electors

A UK citizen living abroad who applied for a vote having been registered to vote as a resident in the UK in the last 15 years. To qualify as an overseas elector the person should no longer be living in the United Kingdom but must previously have been resident here and included in the electoral register (unless they were too young to register). They are registered in the same Parliamentary constituency as before they went abroad.

Anonymous electors

Anonymous registration is available to people meeting certain statutory requirements where, if their name or address were listed on the electoral register, their safety would be at risk. Any other person in the same household as a person at risk is also qualified to register as an anonymous elector.

Opted-out electors

There are two versions of the electoral register - the full register and the "open register". The full register is used only for elections and for preventing and detecting crime. The open register is available to anyone who wants to buy a copy, for example, marketing companies. Electors can opt out of the open register.

European Union citizens

European Union citizens (excluding British, Irish, Cypriot and Maltese citizens who are included in previous categories) are included in the "European and local gvernment electorate" but are not eligible to vote in Westminster Parliamentary elections.

More quality and methodology information on strengths, limitations, appropriate uses, and how the data were created is available in the Electoral statistics QMI.

For England and Wales, electoral statistics are taken from data supplied to the Office for National Statistics by local electoral registration officers. Data for Scotland are similarly collected by National Records of Scotland (NRS). Data for Northern Ireland are collected by the Electoral Office for Northern Ireland (EONI). We collate these statistics for the UK using the data supplied by NRS and EONI. The RPF29 form that underpins this publication does not collect data on electoral registrations by age, sex, citizenship or any other characteristics.

There are at present 650 Westminster Parliamentary constituencies in the UK, made up of 533 in England, 59 in Scotland, 40 in Wales and 18 in Northern Ireland. These boundaries came into effect at the May 2010 General Election. The typical size of constituencies differs between the constituent countries of the UK. It is possible in certain circumstances for someone to be lawfully registered to vote at more than one address. This could include, for example, students who have different home and term-time addresses.

In the year to December 2019, there were delays in receiving forms from electoral registration officers for some of the local authority areas. Because of the priority given to running the general election called for 12 December 2019, electoral registration officers published data during the period of November through to February later or earlier than the nominal 1 December date.

Electoral statistics are available for the two main groups of voters:

• Parliamentary electors - those entitled to vote in Westminster Parliamentary elections

• local government electors - those entitled to vote in local government elections

The difference in who is entitled to vote at Parliamentary and local elections depends largely on residence and citizenship conditions. Local government electors, for example, include those European Union citizens resident in the UK who are not entitled to vote in Westminster Parliamentary elections, whilst Parliamentary electors include British citizens resident overseas who are not entitled to vote in local government elections.

The majority of those registered to vote in local government elections are also eligible to vote in European elections. To be entitled to vote in European elections in the UK, European Union (EU) citizens are required to request the right to vote in this country rather than their home country. Those persons who do not make this request will not be included in the European Parliament electorate.

The local government electorate in Scotland includes 16- and 17-year-olds who are ineligible to vote in European elections. Further information on who can vote in different UK elections can be found on the GOV.UK website.

There are three main reasons why the registered numbers of electors in an area can change from year to year:

• a change in the size of the population who are entitled to vote; for example, because of international migration, internal migration, deaths

• a change in the proportion of the eligible population who actually register to vote; for example, more people registering as a result of better canvassing or because of an election

• changes to the franchise in Scotland in the summer of 2015 to allow 16- and 17-year-olds to vote in Scottish Parliamentary elections and local government elections in Scotland

Quality

Electoral statistics represent the most accurate count possible of the number of people on electoral registers each year. They are subject to full quality assurance procedures, are reliable and provide comparable data across the UK constituent countries.

The electoral statistics we publish are used by Boundary Commissions, the Electoral Commission and central government to help with the improvement of electoral policies and for statutory reviews of Parliamentary constituency boundaries. The statistics are also of interest to Members of Parliament and the general public.

Comparing population estimates and electoral statistics

The electoral statistics in this bulletin give information on the number of people who are registered to vote in the UK - there is no similar collection of data on the number of people who are eligible to vote but who do not register.

We provide mid-year estimates of the resident population and these have sometimes been used as an estimate of the total number of people who are entitled to vote. However, care must be taken in using these data for that purpose as the population estimates include some people who are not eligible to vote and exclude some people who are eligible to vote (for example, overseas electors).

We have also published some research looking at the scope and quality of the electoral register as a likely source of data for measuring population, which is available in the Administrative Data Sources Report on the Electoral Register (PDF, 554KB).

The Electoral Commission continues to conduct research on voter registration, as well as providing information and guidance to both electoral registration officers and the general public. In July 2016, the Electoral Commission published a report into the accuracy and completeness of the December 2015 electoral registers.

Further information to support the electoral statistics, covering methodology, quality and data sources is available from us:

• the Office for National Statistics (ONS) revisions and corrections policy explains how we implement and categorise revisions to statistics

• news on our population statistics can be obtained by subscribing to the quarterly newsletter (email your request to pop.info@ons.gov.uk) or following the Twitter account @richpereira_ONS