The eight-page booklet gives advice on who can vote, how to register and a page on each of the lead campaigns.
It is part of a Â£6.4m awareness campaign organised by the Electoral Commission, which includes a TV advert.
People not on the electoral register have until 7 June to apply for a vote in 23 June's referendum.
Around 7.5 million people in Britain are not registered to vote - and a recent survey by the commission suggested that a fifth of survey respondents were either not registered or were unsure if they were registered to vote.
'Consider a proxy'
The commission says its campaign - "You can't miss it" - is designed to "cut through the noise" that everyone will be hearing about the EU referendum.
It comes a month after the government spent Â£9m distributing a 16-page pro-EU membership leaflet to 27 million UK homes - a move which drew heavy criticism from Leave campaigners.
Alex Robertson, the Electoral Commission's director of communications, says the commission's booklet "gives everyone the information they need".
"This is an historic event and we don't want anyone to miss out," he said.
"A lot of people won't have voted in a referendum before - or will be unsure what the question is.
"If you aren't already registered to vote, then make sure you do it by the 7 June deadline or you'll miss out on the referendum. It's easy and only takes a few minutes online. Tens of thousands of people are doing it every day."
The commission is also advising voters to think about where they will be on polling day. Anyone who is likely to be away on Thursday, 23 June should consider applying to vote by post or via a proxy - a trusted person permitted to vote on their behalf.
Glastonbury festival, which clashes with polling day, is encouraging the expected 135,000 or more attendees to register for a postal vote so that they don't miss out. The Electoral Commission has confirmed that there will be no polling stations on the festival site.
Electoral Commission advertising will run until polling day and appear across TV, radio, video on demand services, billboards, digital and social media.
Bilingual versions of the booklet - which cost Â£2.4m to produce and deliver - will be delivered to households in Wales.
Nearly 140,000 people registered to vote in the final through weeks before the Scottish referendum in September 2014. Over 11,000 applied to register after the deadline - and missed out as a result.
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European Space Propulsion (ESP) Limited blamed disappointing sales for going into liquidation.
Formed by Aerojet Rocketdyne in 2012, it operated from missile maker Thales UK's factory in Castlereagh.
Its offices were opened by the former First Minister Peter Robinson.
He had expressed delight the US company had selected Belfast as its European sales base.
But it never got near its projected Â£13m annual turnover.
A spokesman for the firm said: "We had high hopes, just like the Northern Ireland ministers did.
"We thank them for their support but unfortunately expected sales just never materialised."
As recently as December, then Economy Minister Jonathan Bell talked of ESP as having "brought significant benefits to Northern Ireland".
Employee numbers never got above eight.

North Wales Police had warned supporters to behave at the Racecourse and later confirmed there were no arrests at the match which ended 0-0.
Safety fears meant Chester fans had to travel on official coaches under police escort.
It is the fourth year the fixture has been marked as a "bubble match" - meaning supporters will be kept apart.
North Wales and Cheshire police forces have said restrictions could be reviewed if there was no trouble at the two games this season.
Speaking before the game, North Wales Police and Crime Commissioner Arfon Jones said: "If things go well, it looks as if this bubble business with the restrictions on travelling fans can be lifted which would be great news."
"This is now the only [current] fixture in all the tiers of English and Welsh football that is a bubble, including Premier League and Championship derby fixtures, and I think it is risk averse and disproportionate in terms of policing," he added.
An impartial voting guide for the EU referendum will drop through the letterboxes of 28 million households across the UK from 16 May.
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An American-owned aerospace firm attracted to Belfast by Invest NI and backed by the  Northern Ireland Executive is ending its local operation.
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Police have thanked Wrexham and Chester fans for their "good natured co-operation" at their derby match.