As credit-card issuers raise rates and fees and lower credit limits, consumers face higher-cost debt -- and more work maintaining their credit score.

In some cases, banks' former darlings -- consumers who paid consistently and on time but let their balances ride -- now are being hit hardest, asked to stomach higher interest rates and fees or try their luck with different card issuers.

For instance, some J.P. Morgan Chase %26amp; Co. credit-card customers who have carried a balance for more than two years will be charged a $10 monthly fee starting in January and their minimum payment will rise to 5% from 2%.

Meanwhile, as many as 10 million Citigroup Inc. customers whose interest rates have not changed in two to three years will receive notice in their November statement that their interest rate is increasing by an average of three percentage points.

And in December, American Express Co. will lob a two to three percentage point interest-rate hike across a broad swath of consumers, plus increase the conversion rate for charges made in foreign countries.

Amid rising unemployment and higher delinquency rates, credit-card issuers are cracking down, particularly on the balance-carriers. "Given the current environment banks are starting to get very scared of the backlog of debt they're owed from their current borrowers who have carried balances," said Greg Larkin, a New York-based senior analyst with Innovest Strategic Value Advisors.

"They're trying to purge them from the roles of people that owe them money," he said. "Banks right now want to prove their balance sheet is healthy, that their borrowers pay them back on time."

Another potential issue for firms: They have little hope now of packaging consumer debt into securities and selling it off, given that no one's buying. "There's a stronger risk that this becomes the bank's problem, that it doesn't become the problem of the investor who's invested in the securitization pool," Larkin said.

Ironically, rate hikes are occurring in an overall environment of low rates, with the Federal Reserve's federal funds at just 1% currently. Borrowers with great credit and no or low balances can shop around for deals, said Greg McBride, senior financial analyst for Bankrate.com.

Overall, the average variable rate is about 11.25%, down from 14% about a year ago. "The point for consumers is, don't take this sitting down. If you have good credit, there are better terms available. Shop around," McBride said, describing good credit as a score of 700 or higher.

Still, other data show a slight uptick recently: Average credit card rates rose slightly between Oct. 15 and Nov. 1 to 13.81% from 13.75%, according to CardRatings.com, which logged average rates at 15% a year ago.

Credit score conundrums

Consumers who don't carry balances, but charge hefty amounts each month also should be checking their statements regularly: As credit-card issuers pull down credit limits, some customers may find themselves unexpectedly topping out. That can bring steep over-limit fees and double-digit interest rates going forward.

Twenty percent of banks said they lowered credit lines for their best card customers, while 60% lowered lines for nonprime borrowers, according to the Federal Reserve's most recent survey of senior bank loan officers in October. Meanwhile, 61% said they are applying stricter lending guidelines on existing credit-card lines.

Given all the changes, "we recommend people look at their APR and their credit limits every month," said Bill Hardekopf, chief executive of LowCards.com.

As long as you are able to keep your balance under it, a lower credit limit isn't necessarily a problem. Still, just the fact of a lower limit may well ding your credit score. Thirty percent of the FICO score is based on "amounts owed," including the ratio of your balance to your available credit, called the "credit card utilization ratio." The more you've tapped your available credit, the worse your score. Read more on Fair Isaac Corp.'s site.

If your lender lowers your credit limit, one way to bring your score up is to pay down your debt. Not everyone is able to do that. Another solution is to increase your amount of total available credit, either by asking for a credit line increase on one of your cards or by applying for a new card.

While applying for new credit can ding your score, that negative mark recedes over time, said Ethan Dornhelm, San Rafael, Calif.-based senior scientist at Fair Isaac Corp., creator of the FICO score.

Depending on one's credit profile, "applying for a single card could have a minor ding on your score," he said, "but as you move to the longer term, the impact of the application for credit wouldn't be so recent anymore and would be outweighed by the fact that you increased your available credit and subsequently decreased your utilization ratio" -- thus upping your score.

Opt out of higher rates

If you carry a balance and your issuer lobs a rate hike on that balance, you can opt-out by either calling the credit-card issuer or sending a letter. Hardekopf recommends sending a letter certified mail for record-keeping purposes.