Store card interest rates are usually much higher than standard cards, at around 20-30 per cent in some cases, so be very careful how you use them. It can be especially tempting around Christmas to take advantage of money off deals that the shops are offering, but be aware of the expensive debt you are building up. If you want to benefit from the deal, then try not to leave any debt on the card, pay it off each month so you are not suffering the huge interest amount being added.