Over 46 million people are eligible to vote in Thursday's Brexit referendum, according to provisional electorate figures from the UK's Electoral Commission.
Data collected from 382 local voting areas shows that the provisional size of the UK and Gibraltar electorate is 46,499,537.
The final figure cannot be confirmed until 9pm on Thursday evening, as in some limited circumstances changes can still be made to the registers up to that time.
The provisional figure is slightly higher than that recorded at the 2014 European parliamentary elections, where 46,487,579 voters were registered.
The highest concentrate of voters is in England with almost 39 million (38,956,824) people eligible to vote.
Scotland has almost 4 million (3,988,492), while Wales has just over 2 million (2,270,743) registered voters.
Over 1 million people (1,260,955) in Northern Ireland are registered to vote.
In the British overseas territory of Gibraltar, 24,117 people are eligible to vote.
Polls opened at 7.30am on Thursday and will close at 10.30pm that night.
Republic of Ireland citizens living in the UK are eligible to vote on Thursday, as are Irish citizen living overseas who were born in Northern Ireland and who have been registered to vote in Northern Ireland in the last 15 years.
The original deadline to register to vote was midnight on June 7th.
However, the high volume of of visitors to the government’s registration website in the hours leading up to the midnight deadline, caused it to crash and resulted in the UK parliament passing legislation to extend the registration deadline until June 9th.