The magazine Which? has called for credit charges to be investigated by the OFT. It claims that many consumers rely on the typical APR advertised by card providers to make comparisons between products, but this rate can be hugely misleading.

The magazine claims that cards using the same APR rate could attract very different interest charges based on when the interest charging period begins for each purchase. The current method for calculating the typical APR does not take this into account and therefore is not a useful comparison figure to present to would-be customers. The variation in charges on equal rate cards could be as much as 43%, it is claimed and the magazine even claims that a card charging 11.9% could work out more expensive than a 15.9% card depending on how the interest is calculated.

The only way the typical APR could allow useful comparisons is if every card used a standard interest-free period following a purchase, Which? suggests. There are so many variations in the way card companies charge their interest, a standard method is unlikely to be found quickly and perhaps a better suggestion would be to force companies to show interest charges for a range of standard situations.