Arguments about the potential impact of Brexit on the economy and the public finances have dominated the referendum debate.
Here are what the rival camps are claiming:
:: Brexit campaigners argue that sluggish growth in the EU is holding Britain back and free movement of European workers is hurting jobs and wages for UK nationals. They say it will be in EU members' self-interest to continue to trade with the UK following Brexit and that Britain will be able to boost exports by striking new trade deals with countries around the world - creating around 300,000 jobs.
:: Michael Gove has said the UK will leave the EU's single market and not be bound by its rules, but British firms would be able to continue trading with Europe.
:: The UK pays £350 million a week - or £19 billion a year - to the EU, which could be redirected to British priorities, including by spending an additional £100 million a week on the NHS.
:: The UK could be faced with a "hefty" additional bill from the mid-term review of the EU's 960 billion euro (£750 billion) budget for 2014-2020, which was held back until after the referendum. Additional costs from the migration crisis could force the budget up by billions of euros.
:: A European Parliament report earlier this year highlighted a backlog of unpaid bills totalling 24.7 billion euros (£19.4 billion) which the EU will have to pay down. Vote Leave estimates the UK could be asked to fund £2.4 billion of these repayments, in line with its 12.5% contribution to EU budgets.
:: Boris Johnson has warned the UK could be forced to bail out eurozone countries if the crisis in the single currency worsens, with unknown sums potentially at stake. Despite a 2011 agreement that non-eurozone states will not have to support bailouts of this kind, Vote Leave argues that an article in the EU treaties requiring members to help a country facing "natural disasters or exceptional occurrences beyond its control" could be used to force Britain to chip in.
:: The Economists for Brexit group has forecast that after leaving the EU, output will grow by 2%, competitiveness will rise by 5%, and disposable wages will go up by 1.5%. The group's Patrick Minford suggested that walking away from the EU, not negotiating a new agreement with the EU or putting up any new trade barriers will bring about a 4% gain in GDP.
:: The Institute for Fiscal Studies (IFS) think tank said that while Brexit would mean around £8 billion a year of taxpayers' money no longer going to Brussels, the damage to the economy would wipe out those savings. The National Institute of Economic and Social Research has forecast GDP in 2019 could be between 2.1% and 3.5% lower as a result of a Brexit. The IFS said a hit to GDP of this magnitude would leave the public finances between £20 billion and £40 billion worse off in 2019-20. That could mean austerity measures being extended for two years to deal with the deficit.
:: International Monetary Fund (IMF) chief Christine Lagarde has warned the consequences of Brexit would be "pretty bad to very, very bad". Brexit poses a "significant downside risk" and could see interest rates "rise sharply", she said. The Organisation for Economic Co-operation and Development estimated in April that by 2020 GDP would be more than 3% down on what it would have been if Britain had remained in the EU - the equivalent of £2,200 per household at today's prices.
:: The Remain camp rejects Vote Leave's £350 million-a-week figure for UK contributions to the EU budget, which was branded "deceitful" by Sir John Major and has twice been ruled "potentially misleading" by the independent chief statistician Sir Andrew Dilnot. Sir Andrew found that the £19 billion-a-year figure ignores the UK's £4.4 billion rebate and EU money which comes back to the UK. He put the net contribution in 2014 at £9.9 billion - or £190 million a week.
:: The UK's EU contribution is anyway only a tiny fraction of Government spending, amounting to less than 1% of national GDP. A Treasury document found that this sum would be dwarfed by the expected 6.2% hit to GDP resulting from Brexit, equivalent to £4,300 for every household in the country.
:: Treasury analysis found that Brexit would increase unemployment by 520,000-820,000 within two years and that tax receipts would fall by £36 billion by 2030. Some £250 billion worth of UK trade would be at risk, officials said.
:: The Remain camp argues that if Britain wants to maintain access to the European single market, it would have to continue to pay into EU budgets and accept free movement, as Norway does, without having a say over EU policy. If this was rejected, the UK would face a lengthy negotiation to secure partial access in a Canada-style deal, or tariffs on its exports under World Trade Organisation rules.
:: In a blow to the Brexit camp's claims about striking trade deals, US president Barack Obama warned the UK would be at "the back of the queue" if it was outside the EU. This was because the bigger prize for the US was a deal with the larger bloc, he said.