Remember the old commercials in which a consumer wallowed in embarrassment after his card was declined? Thanks to the CARD Act, those days are back: Issuers must now get a consumer's explicit permission to spend above the limit. No permission? No approval for that transaction. Over-limit fees are also capped at $25 ($35 if you go over twice within six months), less if you went over by just a few dollars. In response, issuers including American Express, Bank of America and Citibank have eliminated over-limit fees altogether. "They're not making a lot of money doing that anyway," Satyavolu says. A Capital One spokeswoman says going over-limit generates a fee on cards that allow it, but several, such as Journey Student Rewards from Capital One (see "For students") have a fixed credit limit that cannot be exceeded. Good move, says Susswein: "Going over-limit can end up being a very costly choice."

Beyond fees, the occasional over-spender must also consider penalty rates. Consumer Action's 2010 credit card survey found that the terms and conditions for some individual cards say going over a credit limit is a factor that could trigger future rate increases. A Chase spokeswoman confirmed that over-limit charges can trigger a penalty interest rate. Other issuers, like Citibank, relaxed their over-limit policies when the CARD Act went into effect February 22, 2010.

Consumers whose monthly charges vary widely, including small business owners, should look first for a card without a limit, Arnold says. Barring that, pick one where exceeding the limit won't trigger a fee or penalty. Bank of America Accelerated Rewards American Express has rates ranging from 12.99% to 20.99% and awards 1.25 points per dollar spent. "We don't charge a penalty rate on existing balances even if the customer is 60 days past due," a Bank of America spokeswoman says, nor do they charge over-limit fees. And Arnold likes the no-fee Clear from American Express: "If you go over you limit, they're not going to ding you." Every time you spend $2,500, the issuer mails a $25 reward card.