Attorney General Eric Holder recently said that legal marijuana businesses need access to bank accounts as a public safety issue. Bankers and pot entrepreneurs hailed those comments as an important step. But they said it will take a change in federal law to make banks truly open their doors.

Although recreational marijuana has been legal in Washington for more than a year, federal law still prohibits banks from dealing with those businesses. Holder said he’s working with the Treasury Department to try to facilitate access to bank accounts.

A Justice Department spokesman said the changes may not take the form of a change in law or new regulations, but instead as "guidance" for prosecutors and law enforcement. Jim Pishue, president of the Washington Bankers Association, said it’s not clear how much protection the new federal guidance will provide banks.

“It depends, I think, on two things,” Pishue said. “One is how strong the guidance is, and the second is, banks will then have to decide individually whether they feel the guidance provides them enough safe harbor for them to enter into banking this business.”

This month the New York Times wrote a front-page feature on marijuana business owners in Seattle paying state taxes with mountains of cash.