According to new research from MyCallcredit, millions of people in the UK are at risk of identity fraud because they fail to cancel credit cards they no longer use.

Identity theft is the UK's fastest-growing crime, and costs the economy an estimated £1.7 billion a year. Identity thieves steal key pieces of personal information and use them to impersonate you and to commit crimes using your name and identity profile. It can take many months before a victim becomes aware of ID fraud.

MyCallcredit is the consumer arm of credit reference agency Callcredit and enables people to view their credit report online. Their research found that at the end of 2005, 31.5 million people in the UK held an average of 2.5 personal credit and charge cards, but around one in three of these cards was no longer active.

Mel Mitchley, Callcredit director, said: “This means millions of people have stopped using a credit or store card without telling their lender, the facility is still available and a fraudster can quite easily use it to rack up debts in someone else’s name without fear of early detection.”

But the risk is not just with existing credit facilities. 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.

Mitchley said: “People need to take care of their ID by checking their credit file and cancelling any unused credit facilities.

“They also need to shred personal documents, including direct mail, before they throw it away.”

It is simply not enough to cut up a credit card you no longer want to use as the account will remain open and will appear on your credit file until you inform the card company.

When you want to stop using a card it is imperative that you contact the card company to cancel it and ask them for confirmation of cancellation in writing.

You should also request your name to be removed from the company's marketing mailing list, particularly if you are moving house.