Rate changes raise or lower the finance charge on your account. At the latest, you also must receive information, before you become obligated on the account, about any limitations on how much and how often your rate may change. Knowing whether a card gives you a free period is especially important if you plan to pay your account in full each month. Without a free period, the card issuer may impose a finance charge from the date you use your card or from the date each transaction is posted to your account. If your card includes a free period, the issuer must mail your bill at least 14 days before the due date so you'll have enough time to pay.
Most issuers charge annual membership or participation fees.
Transaction Fees and Other Charges . A card may include other costs. Some issuers charge a fee if you use the card to get a cash advance, make a late payment, or exceed your credit limit. Some charge a monthly fee whether or not you use the card. Balance Computation Method for the Finance Charge.