It is finally here. After four months of one of the most divisive and poisonous debates in memory, the UK votes on whether to remain part of the European Union or leave it.
Polls opened across the country at 7am, staying open until 10pm, as per normal polling rules. If you're struggling to get to your polling station until late this evening, remember as long as you are inside the station or part of a queue before 10pm, you will be able to vote.
An estimated 49.5 million people are eligible to vote - a record high for the UK.
If you're not 100% sure of the wording (because it was changed!), you will be asked: "Should the United Kingdom remain a member of the European Union or leave the European Union?"
Weather is known to play a fairly big part in turnout at polls. And it could have a particularly big effect in the South East where thunderstorms and torrential rain fell overnight, causing flooding. Northern Ireland and Scotland are also forecast for heavy showers throughout the day.
Unlike general and local elections, votes will not be counted in Parliamentary constituencies, instead county councils. There will, however, be a single count for Northern Ireland and a single count for Gibraltar.
The Electoral Commission expects an official decision around "breakfast time" on Friday.