Millions of Britons are putting themselves at risk of identity fraud because they fail to cancel credit and store cards they no longer use, warns one credit report service.

Research by MyCallcredit revealed 31.5 million people in the UK hold on average 2.4 personal credit and charge cards but one in three are no longer active.

Fraudsters can take advantage of these unused accounts, running up debts in someone else's name without the fear of early detection.

"The risk is not just with existing credit facilities, it's also with ones offered to people through direct mail," said Callcredit director Mel Mitchley.

"If you've been pre-approved for a credit or store card and you throw that information in the bin without shredding it you're handing a fraudster an open invitation to impersonate you and get credit in your name."

The service suggests people check their credit file and cancel any unused credit facilities, and also shred personal documents before throwing them away.

Consumers are advised to contact their lender as cutting up a card or leaving it in a drawer is not enough to protect against identity theft.