We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.

Interest calculation methods - Which? super-complaint

Office of Fair Trading (OFT): “APR is certainly the key item [consumers] look at when making comparisons. Even though they may not fully understand what this means, they know to look for a low figure”

However, the advertised APR does not reflect the way in which interest charges are actually applied. The existence of different interest calculation methods means that when two consumers use two different credit cards with the same APR in exactly the same way, they can end up paying very different levels of interest.

For instance, the HSBC MasterCard and Sainsbury’s Bank MasterCard both charge an APR of 15.9%, however consumers who use the two cards in the same way may end up paying up to £25 more a year with the Sainsbury’s Bank MasterCard than the HSBC MasterCard.

See our full report:


Interest calculation methods - Which? Super-complaint 243 Kb

See the response to our super-complaint: 

Credit card interest rate calculations - Which? super-complaint response 169 Kb