New technology is creating a worrying form of "silo working" at small firms, where information is not freely available to the whole organisation.
A survey of 100 small firms employing up to 250 people has found that "do it yourself" IT is causing the problem.
The survey, commissioned by Apple database firm FileMaker, says the increasing IT skills of the office worker, coupled with the ease of use of modern technology, is creating new and worrying "micro-silos" of data at UK SME businesses.
This is putting productivity, compliance and the bottom line at risk, said FileMaker.
Although the technology available to UK businesses has never been better, end-users are taking IT policies into their own hands.
In doing so, they are creating dangerous micro-silos of data within their organisations, typified by crucial documents being locked away on individual PCs and in e-mail accounts, creating "a wilderness of data outside existing policies and processes", said FileMaker.
The survey found that 64% of IT managers questioned believed their business suffered from a micro-silo mentality when it came to company information, with almost half (45%) believing this is a result of poor IT management.
"IT free-styling" is now much more prevalent, with 77% thinking it is easier to create/customise critical business applications than three years ago, resulting in essential data residing with single users.