Credit card companies seem to be constantly under attack these days. They have recently been forced by the Office of Fair Trading to restrict the charges they impose for late payments and now Which? have lodged a 'super complaint' with the OFT about the inconsistent way in which APR's - the annual percentage rates - are calculated. The OFT now has one month to decide whether to investigate further.

However, whatever the outcome the credit card companies are sure to fight back with ever more resourceful ways to boost their coffers at your expense so it's worth reminding ourselves of some of the tricks used and how to avoid them. Our short guide should help you keep more of your hard-earned cash in your pocket and not theirs.