Inquiry Disclosed

Richard Cordray, installed four months ago by President Barack Obama as the bureau's first director, disclosed the overdraft inquiry in general terms on Feb. 22. In a recent interview, he said the agency is looking at "a lot of data" as it coordinates with other federal regulators on the subject.

"We want to work with the other agencies to develop, as much as possible, common guidance on this," Cordray said. "We intend and expect to have an action plan on it by the end of the year."

Cordray previously has said the agency plans enforcement action against banks that "exploit consumers with deceptive marketing."

Before it officially started work July 21, the bureau had focused its attention on mortgages and payment cards, the two major forms of consumer credit. The only clue to its interest in checking accounts was the name of the team it fielded in Washington's 2011 summer softball league: The Overdrafts.

The money at risk for the banking industry could exceed the impact of the Fed's 2011 cap on debit card swipe fees, which may cost the 10 largest banks $4.6 billion a year.

In 2011, Wells Fargo's retail division took in $4.3 billion from fees, including overdrafts, roughly equal to a quarter of the bank's net income for the year, financial disclosures show. That same year, JPMorgan brought in $3.2 billion in fees related to lending and deposits, disclosures show.

Greg McBride, senior analyst with Bankrate.com, said tighter rules could lead financial companies to make up for the loss in revenue by raising fees on basic checking services.

"The economics of the checking account become vastly different without that overdraft income," McBride said in an interview.

Consumer activists and lawmakers have long criticized overdraft protection as a system designed to build profits rather than protect customers. They say the penalties are too high, that some banks manipulate the timing of transactions to maximize fees and that customers were being automatically enrolled without understanding the potential drawbacks.