Loose-lipped employees are spilling company secrets in coffee shops, restaurants, cafés, parks and libraries across Britain.
But it's Londoners who are the worst offenders, with around half having overheard at least one private business conversation in a public place, and 47 per cent having had one.
MeetingRooms.com, which conducted the survey, defined private as anything that the company wouldn’t want the general public to hear or know about.
When it comes to eavesdropping on a private business conversation in a public place, the South West came second, followed by the South East and then the East of England and East Midlands.
And in terms of actually having a private business conversation in public, the West Midlands came second, followed by the South West and then the South East.
"Careless talk can cost any business a lot of money and a lot of embarrassment; whether it's a competitor stealing your new product idea or an investor overhearing sensitive financial information," Caleb Parker, chief executive of MeetingRooms.com, said.
"It's clear from the study while companies spend thousands, if not millions, every year protecting their data from hackers, their biggest data security threat is people sharing too much information in a public place."
Have overheard a private business conversation in a public place:
Have had a private business conversation in a public place: