Votes in the in/out referendum on Britain's membership of the European Union will be counted overnight, the Electoral Commission has announced.
A referendum date has not yet been set, but the government has promised it will be held before the end of 2017.
David Cameron is in the process of renegotiating Britain's relationship with the EU, ahead of the vote.
The counting of votes will begin as soon as the polls close, at 22:00, the elections watchdog said.
Jenny Watson, chair of the Electoral Commission, said this would mean "voters and campaigners will know the outcome of this historic poll as quickly as possible".
"I have no doubt that electoral administrators will work hard to deliver the poll, whenever it is held, and the Electoral Commission will be supporting them in their work and making sure they have the right plans in place to deliver what is needed," she added.
Though no date has been set for the referendum, David Cameron has been forced to rule out holding the poll on 5 May 2016, the same day as national elections in Scotland, Wales and Northern Ireland. The prime minister is understood to want an early vote.
The watchdog could not confirm how the count would be conducted or declared, saying it was "still in the planning stages" for the vote.
The elections watchdog has proposed a change to the wording of the referendum question - which has been accepted by the government, although the final decision will be taken by Parliament.
It proposes that voters are asked: "Should the United Kingdom remain a member of the European Union or leave the European Union?"