With so many choices in the world of credit cards one item stays a constant - the changing APR or "Annual Percentage Rate."

Many cards holders are unaware that the APR on a credit card is not a constant. The rate changes depending on a variety of financial calculations.

For instance, cash advances usually carry the highest rate while purchases using your card is at another rate. When you signed up for you 0% APR card and transferred all of your balances my likely the card came with a grace period on the balance. Once that time ends a new APR comes into play. Confused? Learn more here in Low APR Credit Cards May Not Be Created Equal - Know Your Cards APR and How it Changes.