Watch out for costly credit-card practices.

For more than 25 years, Cathy Roper, an accountant from Missouri, has paid her credit-card bills and loans on time. So she was shocked to learn that her bank had cut her card limit to less than her outstanding balance, then charged her a fee for being over the new limit. Roper, who reached us through a Consumers Union Web site, was alert enough to notice the fee and angry enough to complain. Others might not be so aware or so persistent.

Among the reports we've received from a growing number of consumers are hefty late fees triggered when credit-card companies don't process on-time payments promptly; "over the limit" fees added when finance charges push balances too high; and interest rates raised even when the consumer has neither missed a payment nor been late with one.

A Florida man told us that within a month of using a 1.9 percent "convenience" check, his credit-card company raised his interest rate to 23.99 percent. He had written a single check for about $11,000 of his $20,000 limit and charged nothing else to the account. He didn't know that the card issuer considered him a risky customer once he used more than 50 percent of his credit limit.

Such practices are contributing to record credit-card debt in the U.S. According to a September 2006 report from the U. S. Government Accountability Office, more than half the consumers who hold credit cards carry a balance. Thirty-five percent of active cardholders were charged a late fee in 2005. At least some of those payments were late because of tight turnaround times set up by card issuers.

Terms spelled out in a credit-card agreement might be buried ...