Credit card companies could be forced to improve the information they give customers to help them to choose the best deals, after the Office of Fair Trading announced a review into credit card pricing today.

John Fingleton, of the OFT, said: “This will consider how pricing information might be improved so as to enable better product comparison by consumers without stifling valuable competition and innovation that benefits consumers."

The move follows a super-complaint lodged by Which? with the OFT in April over the lack of transparency in credit card interest calculation methods. Alena Kozakova, of the consumer group, said: "Two people who have two different credit cards with the same APR, and who use their credit cards in the same way, could be paying very different levels of interest."

Today, Which? branded the watchdog's response “shy”. Peter Vicary-Smith, the consumer group’s chief executive, said: “We presented the OFT with a simple problem – that multiple interest calculation methods were preventing consumers from picking the best credit card – and, instead of tackling this head on, it has chosen to do a wider review.”

Which? said that there were six key features other than the APR which affected cost but were not sufficiently explained to the consumer. As a result, customers were prevented from making an informed choice on the basis of price.

The review announced today by the OFT will explore the issues surrounding the cost of credit on credit cards including purchases, cash advances, introductory offers and payment allocation. It is expected to take six months and will involve consultation with the credit card industry, consumer groups, Government bodies and regulators.