In 2005, about 44% of credit card issuers surveyed by the non-profit group Consumer Action assessed universal default interest rates. Those issuers included Citigroup, Washington Mutual, HSBC Holdings and Wells Fargo, according to the group.
"Even consumers who always pay on time cannot avoid the price abuses," said Michael Donovan, an attorney at the National Consumer Law Center.
Other questionable tactics involve applying penalty interest rates retroactively to prior purchases and lowering loan limits that trigger fees and higher rates.
Based on Federal Reserve figures, Plunkett estimated outstanding credit card debt amounted to $750 billion to $800 billion in November 2006. The industry has more than 640 million cards in circulation.