The data stored by Brits on their personal mobile phones can be easily used for ID theft purposes, especially because of the minimal security measures they take to guard the data, warned Credant Technologies.

The endpoint data protection vendor conducted a survey three weeks ago by questioning 600 commuters at London railway stations (mainly London Liverpool Street) about their mobile phones, typical usage, and the types of sensitive information stored on their handsets.

The survey found that 80 percent of mobile phone users store information on their phones that could easily be used to steal a person's identity.

Among the worrying results, 16 percent admitted that they have their bank account details saved on their mobile phones; 24 percent used the handset to store their pin numbers and passwords; 11 percent keep their social security and inland revenue details on the device; 10 percent store credit card information. Yet despite holding such sensitive information, 40 percent of respondents admitted they fail to protect their devices with a password.

Mobile phones are also a security concern for businesses, especially since most modern handsets are now capable of storing large amounts of data. Most users (99 percent) admitted that they use their personal devices for some sort of business use, despite 26 percent being instructed by their employer not to do so.

According to a Credant spokeswoman who took part in the survey itself, 63 percent of people questioned said that their employer also provides them with a work phone. Yet despite this, most people (99 percent) admitted to storing work information on their personal handsets.

35 percent said they receive and send business emails on their personal handsets; 77 percent keep business names and addresses on it; 30 percent use it as a business diary; 17 percent download corporate information (typically documents and spreadsheets); and 23 percent store customers information.

According to Credant, all this mobile phone data means that approximately 4.2 million Brits are vulnerable to ID theft. This was extrapolated from figures obtained from the Department for Transport which showed there are 70 million phone users in the UK.

"Once you have access to someone's emails, passwords, birthdays, business diary, documents, children's names and pets you can easily masquerade as that person, sending out emails under their name, read all their corporate data and get to see every personal detail of their life," said Paul Huntingdon - Public Sector Director at Credant in a statement."

"People are ignorant to how easy a professional thief could take over their life and effectively destroy it," he added. "It is therefore imperative that all mobile phone users, even with the most basic handset, password protect and encrypt them."

There are currently no accurate figures for the number of mobile phones that go missing or are stolen in the UK, although a recent survey found that 60,000 mobile phones were left in London's black cabs (taxis) within a six month period.

"The really worrying discovery was that 40 percent do not protect their devices with a password," the spokeswoman told Techworld. But she also reckoned this figure was probably higher in reality. "How many do you know that protects their mobile phone with a password?"

"This means it is very easy for someone do a lot of damage," she added. "Imagine someone like the MD of a company mislaying his or her mobile in the cafeteria. A disgruntled staff member finding the boss's PDA that has no password protection, could easily do a lot of damage, like sending out a malicious SMS or email."