What is the difference between a fixed APR and a variable APR?
A fixed-rate APR or fixed APR sets an APR that does not fluctuate with changes to an index. This does not mean that the interest rate will never change, but the issuer generally must notify you before the change occurs, and in most circumstances can apply the higher rate only to purchases and other transactions you make after you get the notice.
A variable-rate APR or variable APR changes with the index interest rate, such as the prime rate published in the Wall Street Journal. The cardholder agreement will say how a cards APR can change over time.
You should be able to find a copy of the agreement on your card issuers website, and you can request a copy from your card issuer if it is not there. If you have any questions, you should contact your card issuer.