OUR banks, it seems, are not playing fair when advertising loans and credit cards.

A poll by Moneyfacts, the price comparison website, found that only 52 per cent of borrowers actually receive the publicised interest rate. This falls well short of the 66 per cent required by new credit laws.

The regulations aim to ensure that two thirds of applicants receive the annual percentage rate (APR) for which they apply, especially if the lender has a pricing-for-risk strategy, which penalises the less creditworthy with higher interest rate charges.

Credit industry insiders say that they are not surprised that entrants to the credit card market and established players launching new products are finding it particularly hard to comply with the regulations.

Barry Stamp, joint director of checkmyfile.com, a business that advises people on their credit files, cites Barclaycard’s latest offering, at 15.9 per cent, and Halifax’s recent decision to raise the typical interest rate on its One credit card from 9.9 per cent to 12.9 per cent as evidence of lenders belatedly changing offers to meet the new laws.

Nick White, head of personal finance at uSwitch.com, a price comparison website, wants banks and credit card companies to publish figures to prove that they can meet the 66 per cent rule.

The Office of Fair Trading has responsibility for policing the advertising of banks and credit card companies, but it has not taken action against a single business since the new regulations came into force last autumn.

Yet if you think that the failure by the banks to meet the 66 per cent target is just their problem, you would be wrong.

Every time that you apply for a loan, the banks search your borrowing past with the credit reference agencies. This leaves an imprint on your credit file. If you record more than 20 credit searches in a year, you may become a risk that reputable lenders want to avoid.

Mr White says: “You do not know if you will get the interest rate unless you apply, and if you do apply and are turned down, then your credit rating is damaged.”

Borrowers applying for a market-beating personal loan should be particularly cautious, he says. Both Northern Rock and Barclaycard’s 5.7 per cent loan offerings are priced for risk. An applicant with a chequered credit history could pay up to 24.9 per cent for the Barclaycard loan and 14.9 per cent for Northern Rock’s deal.

Yet do not let the fear of rejection stop you from applying for a loan or credit card. Setting up a card account costs lenders £180, plus management fees of £15 a year. If you have fewer than three credit searches to your name over the past year, you may be judged as financially inactive and not worth lending to.

Apathy may also have a price if you hold a credit card in your wallet from some of the high street’s big banks. Royal Bank of Scotland charges 17.9 per cent interest on its Classic MasterCard, while NatWest’s standard credit card has interest of 18.4 per cent. Customers of Barclays who miss out on Barclaycard’s typical rate can pay interest charges of 18.9 per cent or 25.9 per cent.

Credit cards are one of the few products where customers will often know the price only when the plastic lands on the doormat. You may wish to take out a deal charging just one interest rate, such as the MBNA Platinum Plus card, which is priced at 6.9 per cent. Co-operative Bank’s flat rate platinum credit card, which has an APR of 8.9 per cent, is also competitive.

If you are angry about being given a higher rate than advertised, you can exercise your rights under the Consumer Credit Act by returning the card. All credit deals offer a five-day cooling-off period.

Ask yourself if you want the card and look at the price; you may decide that it’s not worth the hassle.