[8] The campaign was co founded by Bristol based businessman and UKIP donor Arron Banks, with property entrepreneur Richard Tice and early financial backing from Jim Mellon.

[9] As the campaign was being renamed Leave.EU,[10] UKIP leader Nigel Farage gave a public endorsement at the party's annual conference in Doncaster on 25 September 2015.

[16] The campaign petitioned the BBC, ITV and Sky over their alleged conflation of the European Union with the continent of Europe in their output, which it said was an example of media bias.

[21] Leave.EU and Grassroots Out organized Bpoplive for 8 May 2016, the day after local and regional elections, in an attempt to reach the key youth demographic, but the event was cancelled.

[26] In April 2019, Channel 4 News reported that an anti-immigration viral video produced by Leave.EU during the referendum campaign was faked, and that the group appeared to have staged photos of immigrants attacking women in the United Kingdom.

On 1 October 2020, Leave.EU were forced to apologise and pay damages for libel to Labour MP Naz Shah after they made a social media post which accused her of being a "grooming gangs apologist".

[30] On 1 November 2018, the Electoral Commission referred Banks and Liz Bilney to the United Kingdom's National Crime Agency regarding the source of money used to fund Vote Leave's activities during the referendum campaign.

[31][32] On 13 September 2019, the Metropolitan Police halted their investigation into Leave.EU's spending during the referendum campaign due to insufficient evidence, on the advice of the Crown Prosecution Service (CPS).

[33] Later in the month, the National Crime Agency concluded that it had "found no evidence that any criminal offences have been committed under PPERA or company law by any of the individuals or organisations referred to it by the Electoral Commission" with regards to spending during the EU referendum campaign.

[37] In an attempt to continue using their .EU internet domain name after the UK had left the European Union, the organization moved its registered address to the Republic of Ireland at the end of 2020.