Nearly one in 10 people believe they have fallen victim to identity fraud, according to a survey.
Identity theft could lead to theft from your bank account
People aged under 30 are most prone to falling victim because they are the poorest at protecting personal details, the survey suggests.
Two-thirds in these groups admitted to giving a PIN or bank details to friends and family and 28% did not know a utility bill could be used in ID crime.
The poll of 2,200 adults by YouGov was commissioned by energy firm Npower.
The survey revealed widespread ignorance over how to combat identity fraud.
About eight out of 10 people surveyed among the under-30s age group did not know what their credit rating was.
Moving house was pinpointed as a particularly dangerous time, as far as falling victim to identity theft is concerned.
The survey found that many people's energy bills and bank statements went astray when they moved.
"August is the most popular time of year for moving property, therefore the risk of ID theft is increased," said Npower spokeswoman Zoe Coombs.
"The under-30s are at higher risk of becoming victims or of putting others at risk as they are more likely to be nomadic, living in rented properties, moving out of university halls and so on."
Fraud experts recommend that people make use of the Post Office's mail redirection service, as well as shredding unwanted personal documentation.
HOW TO AVOID ID THEFT
Do not use your mother's maiden name or place of birth as a security password
Check your credit record annually
If you move, make sure you let your bank know
Shred or rip-up post before throwing it in the bin
Never use the same password for all your accounts
Do not carry address details in your wallet
The most recent government estimates put the total cost to the UK of identity fraud at £1.7bn a year.
And according to CIFAS, the UK's fraud prevention service, identity theft has risen over five-fold from 20,000 cases in 1999 to 137,000 in 2005.
However, Martin Gill, identity professor of criminology at Leicester University, said the actual instances of ID thefts were probably far higher.
"It is relatively easy for a thief to steal someone's identity and people - particularly the under-30s - aren't as cautious as they should be when it comes to safeguarding their own personal details and those of others," Professor Gill said.
"At that age it really isn't seen as important," he added.