The referendum to decide on the UK's membership of the European Union is on Thursday 23 June 2016.
It will put the question "Should the United Kingdom remain a member of the European Union or leave the European Union?"
Voters will have to mark an X in either the 'Remain a member of the European Union' box or the 'Leave the European Union' box.
You must be registered to vote to be able to take part in the referendum.
The deadline to register was originally midnight on Tuesday 7 June, but this was extended until midnight on Thursday 9 June, after a computer glitch meant some people were unable to submit their applications in time.
Who can vote in the referendum?
You can vote in this referendum if you are registered to vote in the UK, are 18 or over on the day and are:
- A British or Irish citizen living in the UK
- A Commonwealth citizen living in the UK who has leave to remain in the UK or who does not require leave to remain in the UK
- A British citizen living overseas who has been registered to vote in the UK in the last 15 years (For those who were too young to register when they left the UK, their parent or guardian must been have registered)
- An Irish citizen living overseas who was born in Northern Ireland and who has been registered to vote in Northern Ireland in the last 15 years
- A citizen of Gibraltar
Do I need to register?
If you aren't already on the electoral register and you want to vote, then yes. You can check with your local authority's electoral services team if you are worried that you are not on the register.
If you voted at last month's UK-wide elections, there is no need to register for the EU referendum unless your name or address have changed since then.
Who is banned from voting?
The following are barred from voting in the EU referendum; anyone other than British, Irish, Gibraltarian and qualifying Commonwealth citizens; convicted prisoners; anybody found guilty of electoral fraud within the last five years; people who are subject to any "legal incapacity" which impairs their judgement.
How do I register to vote?
If you live in England, Scotland and Wales, you can register online at www.gov.uk/register-to-vote through the government's gov.uk portal.
If you are eligible to vote and live abroad, register in the same way.
The online service is also available in Welsh.
If you live in Northern Ireland, you will need to register using a different site, found here.
If you are an Irish citizen living overseas who was born in Northern Ireland, you need to go to the Electoral Office for Northern Ireland website and download the correct form.
By when do I need to register?
Applications to vote must now be submitted by midnight on 9 June, in order to vote in person on 23 June.
How unusual is it to have the deadline extended?
Online voter registration has only been around (in England, Scotland and Wales) since 2014, and the deadline for last year's general election - the new system's first major test - passed without any hitches.
Computer glitches are not new to the world of politics however. The deadline to register to vote in Labour's leadership contest was briefly extended in August after technical problems hit the party's website.
What do I need to register?
You need your National Insurance number and your passport, if you're a British citizen living abroad.
If you don't have a National Insurance number card, (they were axed in 2011) or the letter that replaced them, the number should be on your payslips, or on official letters regarding benefits or tax credits, or on a student loan application.
How do I vote?
Once you have registered to vote, there are three ways you can vote in the EU referendum.
- In person at your polling station: You will receive a poll card in the post telling you where your polling station is and will be able to check online on the government's website. Polling stations will be open from 07:00 BST to 22:00 BST on Thursday 23 June 2016. Any voter who arrives to vote before 10pm and is still waiting to vote at 22:00 BST will be able to vote. In Northern Ireland, you have to take a form of photo ID.
- By post: To apply to vote by post, you needed to have completed a postal vote application form. Once you had completed and signed your application form, it had to be sent your local electoral registration office by 17:00 BST on Wednesday 8 June. Their contact details can be found here. A ballot paper will then come in the post. For overseas voters, there may not now be enough time for ballot papers to be posted out from the UK, completed and posted back again and the government's advice is that you should consider voting by proxy instead.
- By proxy: (allowing somebody you trust to vote on your behalf). You need an application form. It has to be returned to your local electoral registration office by 17:00 BST on 15 June 2016. You have to state why you cannot vote in person. Your proxy must be registered and eligible to vote.
- To vote by post or proxy in Northern Ireland, you had to download a form at the Electoral Office for Northern Ireland website by 17:00 BST on 3 June 2016.
- If you are suddenly incapacitated, or taken ill on polling day, you can apply for an emergency proxy up until 17:00 BST on the day.
What if I am registered at two addresses?
You might be registered at two addresses but it is a criminal offence to vote more than once.
What if I am moving house?
If you move between the registration deadline and polling day, the electoral commission recommends you contact your local electoral services office at your local authority for advice. Search for the right one here.
What about if I am in the armed forces?
If you're a member of the armed forces, or the spouse or civil partner of someone in the armed forces, you can register to vote as a service voter or as an ordinary voter.
If you're based overseas or expect to be posted abroad it makes sense to register as a service voter. This allows you to be registered at a fixed address in the UK even if you move around.
Service voter registration lasts for five years.
Can I get help if I have a learning disability?
Yes. The Electoral Commission's voting guides come in various formats on their website.
There are also various languages.
People with a disability can get help completing an application, but the person who wants to register to vote has to make the declaration. In England and Wales, a person with the relevant power of attorney can also make this declaration.
What happens if I don't register?
You won't be able to vote.
Is it compulsory to vote?
No, people cannot be forced to vote.
When will the vote happen?
The referendum takes place on Thursday, 23 June 2016, between 07:00 and 22:00 BST.