Retroactive rate increases

Issuers can't raise rates on an existing balance unless you're late by 60 days or more. No longer will they be able to punish borrowers for late payments on unrelated accounts under the practice of universal default or due to "anytime, any reason" clauses.

If the cardholder does trigger the default rate because of a 60-day delinquency, the bank must restore the lower rate once the cardholder demonstrates six consecutive on-time payments. This provision takes effect in August 2010.

Rates can't be raised in the first year after issuance, and promotional rates must last at least six months.

Caveat: Issuers can raise rates at any time for any reason on new balances with 45 days' advance notice. Cardholders will still need to read correspondence from their creditors.

DEBT-TO-LIMIT RATIOS

Her debt-to-limit ratio on the card suddenly zoomed up from 64% to 94%, and she expects her credit score will be damaged. The ratio is a key component that credit bureaus use to determine creditworthiness. "It's not right," said Mazzera, a project assistant at a construction company. "I worked very hard to keep my credit."

Mazzera is part of a growing number of Americans who are seeing their credit limits slashed. Even people with good jobs, low balances, and solid payment histories could be seeing their credit scores slip through no fault of their own. About 16% of customers had their limits reduced between April 2008 and October 2008, according to a recent study by Minneapolis-based FICO (FIC), which developed the Fair Isaac scoring model used by credit bureaus to evaluate default risk.