The bureau has told agents they can ask phone companies to surrender records voluntarily, the Washington Post reported.
The FBI this month sent its field agents an "emergency letter" template to be sent to phone companies when they need records, the Post reported.
The new rules came before the release of a Justice Department report detailing the bureau's abuses of previous phone record collection policies. It said agents didn't always follow guidelines and treated non-emergencies as if they were emergencies.
Under the new procedures, agents can ask for phone records verbally in emergency situations, the newspaper reported.
"Emergencies will still come up. If we have a child kidnapping or a 'ticking bomb' terrorist threat, we will ask the telecommunications carriers to provide records under the authority provided by law," FBI Assistant Director John Miller told the Post.
The new rules include "an audit trail to ensure we are doing it the right way," Miller told the Post.