Banks are building up secret blacklists of thousands of unscrupulous firms to prevent customers losing their hard-earned cash.
The lists include copycat firms which charge excessive fees for official services such as passports, driving licences and European Health Insurance Cards.
Others trick shoppers into signing up for costly subscriptions for diet pills or anti-wrinkle creams, or offer too-good-to-be-true investment opportunities.
Its blacklist includes some photography and modelling agencies, ‘free trial’ merchants, timeshare sellers, firms selling computer software and security packages as well investment companies.
Lloyds Banking Group, which includes Halifax and Bank of Scotland, feeds the information it receives from customers into a fraud prevention system.
Paul Davis, retail fraud director at Lloyds Banking Group, says: ‘Every transaction a customer makes is given a score between 0 and 1,000. If it is over a certain amount, say for example 500, we would consider it risky and block it.’
Mr Davis says about 1 per cent of payments are registered as high-risk.
He adds: ‘Customers can make a real difference when it comes to helping us in the fight against fraudsters. It is vital that they let us know of any payments on their statements that look suspicious.’
Francis Green, 80 from south Hertfordshire, would have lost £89 if Bank of Scotland, part of Lloyds, had not stepped in to block a payment earlier this year.
She had seen an advert online last December for a free 30-day trial of slimming pills and paid by card for the £3.50 postage cost.
In January, after the pills arrived, Francis received a call from her bank telling her it had stopped an £89 payment to the firm.
Francis, a retired public relations executive, says: ‘There was no mention of £89. I called the company and it said if I did not notify it after so many days of receiving the pills, it meant I had agreed to a subscription.’
If customers notice a transaction on their statement they do not recognise, or dispute, they should contact their debit or credit card provider and make what is known as a ‘chargeback’ request.
The card provider is then obliged to refund the money you lost while it investigates. If it finds the merchant has breached a contract with you, you will be permitted to keep the refund. If it finds the merchant has fulfilled its responsibilities or not acted unfairly, the bank could claw the money back.