Over-limit fees: The average fee on those cards is $30.18. Contrary to what many people believe, a purchase that takes you over your credit limit will not necessarily be denied. Instead, you’ll be stuck with an over-limit fee, which can be assessed every month until your balance is under the limit. The fee can be as high as $39 at Citibank and MBNA. Many banks now use average daily balances to determine if you’ve exceeded your limit at anytime during the billing cycle, instead of the ending balance on your monthly statement. This can trigger an over-limit fee even if you are not over limit at the close of the billing cycle.