Britons risk fraud by carrying PINs Being negligent could include having a PIN reminder next to your bank card in your wallet, so that if it is stolen, a fraudster could easily impersonate you. The burden of proof lies with the bank and it's up to them to show that you authorised a payment or failed to protect your debit card details or PIN. However, in many cases banks will simply refuse to pay you back if your PIN has been used. Fraud prevention group Alaric said recently that a third of Britons share their PIN with their partner, while four per cent of us have let our children know our PIN. Alaric also analysed how often people change the PIN for the credit or debit card they use most often, finding that 40pc of men have changed it in the past year - compared to just 25pc of women. David Divitt, principal fraud consultant at Alaric, said: "Given the number of times that people are sharing their PIN with others, we would hope to see PINs being changed much more regularly. For women especially, who seem to be much more relaxed than men about the need to protect their cards, it is worrying that 25pc said they had never changed the PIN, and another 41pc said only when they first received their card. While crooks can get hold of your PIN by stealing your handbag, they also take people's numbers using a technique called 'shoulder surfing' They look over your shoulder as you tap in your PIN and then steal the card. Criminals can also clone your card by attaching a device called a skimmer on a cash machine, and by using a pinhole camera which films you tapping in your pin.