Unlike fixed rate credit cards, variable rate credit cards impose APR that fluctuate according to indices such as the Prime rate. The prime rate is dependent on the amount of money that can be borrowed by banks in the United States from the Federal Reserve. Cuts made to these reserves will bring down the rate and thereby affecting the interest rate they charge upon your card. However, great care is taken against the rates falling too low and making the company suffer major losses. Thus, there is usually a floor-rate implemented on these cards. Unfortunately, when prime rates escalate, there are no ceiling-rates to protect card users. Customers have to literally go with the flow if they decide on variable rate credit cards.
On the other hand, it should not be assumed that a fixed rate card will impose APRs that will never change. The term 'fixed rate' here would be better explained as a rate that is stable for a longer period of time as compared to variable rate cards. Companies can merely issue you a 30-day notice in writing and your APR can suddenly jump a percentage or two, with or without your consent. One such example is the introductory low APR promotions that companies use to enlist new credit card users. After 6 to 12 months of 0% APR, card companies can immediately change your fixed rate credit card APR to a figure that is higher than most cards without the introductory 0% APR.
Adam Goldman recommends Find Credit Cards to find an HSBC NV card.

