Banks are quietly changing the terms of millions of credit card accounts as they brace for a tough new law that will limit rate hikes, according to a recent commentary in the Los Angeles Times.

The Credit Card Accountability, Responsibility and Disclosure Act (P.L. 111-24), which President Obama signed in May, will be phased in between August and February. The law would restrict interest rate increases unless a credit card has a variable rate.

Two major lenders have already switched their cards with fixed rates to variable rates. Bank of America has notified some customers that "as a result of a change in our business practices, your annual percentage rate will use a variable rate formula based on the U.S. prime rate."

JPMorgan Chase is also swapping variable rates for cardholders’ fixed rates. Representatives of Wells Fargo, Citibank and American Express said that each company had no plans at the moment to change fixed-rate accounts to variable accounts, but didn’t rule it out down the road.

In response to the news about credit card companies changing their practices, Senate Banking Chairman Christopher Dodd (D-Conn.) wrote to federal banking regulators urging them to warn credit card issuers that they will be accountable for any unfair interest rate increases on consumers prior to new legislation going into effect Feb. 22.

Dodd asked Federal Reserve Chairman Bernanke and four other regulators to prevent issuers from raising interest rates on existing balances without justification. Dodd wrote that the new law requires that all interest rate increases that took place this year be subject to a mandatory six-month review by regulators. "I ask you to immediately notify all credit card companies under your respective jurisdictions that they will be held accountable for all interest rate increases during this time period and will be subject to the review requirement once it takes effect," Dodd wrote.