Credit card holders can reduce unnecessary penalties by examining the fine print of their user agreements. Many cards allow for interest-free purchases if they are repaid within a grace period; but spenders should know that providers are abbreviating that period from 30 days to 20-25 days, or eliminating it completely. A fixed interest rate also does not mean that the issuer cannot hike the interest rate; however, they must provide 15 days' notice of any rate change. Card users can avoid surprises by opening and reading all mail from their credit card provider. Under the 2009 Card Act, there are two types of penalties a card company can charge for a late payment: a one-time fee of as much as $35, or a change to the interest rate if the cardholder is 60 days late with a payment. The law also requires that companies review accounts and remove penalty rates after an individual makes timely payments for six consecutive months. Consumers should be aware that a late payment on one card could earn a penalty rate on other credit cards, even if those have been paid on time. Users should check their accounts regularly to see if they are being charged a higher interest rate. Cardholders also should know that many balance transfer checks charge a fee of 3 percent to 5 percent of the check's amount. Consumers who pay excessively high interest rates may be able to negotiate a lower rate or use a balance transfer credit card.