The bank doubled down on promises to use legal action if the Consumer Financial Protection Bureau brings an enforcement action against it related to fraud on the Zelle platform, saying in a statement that it would "not hesitate to seek assistance from courts."

Industry participants say more direct communication between fintechs and federal regulators could help avoid bad outcomes. Some underused legal tools could help bridge the gap.

A bill from Sens. Richard Blumenthal, D-Conn., and Elizabeth Warren, D-Mass., and companion House legislation from Rep. Maxine Waters, D-Calif., would change the Electronic Fund Transfer Act to guard consumers against losing money in authorized transfers that involve scams

The agency admitted navigating the different rules and regulations involved in its four existing lines of credit proved time consuming and confusing and kept some lenders from offering them altogether.

Nine federal regulatory agencies are requesting comment on a rule that would create data standards for supervisory information collected and submitted to financial regulators.

The federal Project Fortress initiative provides defensive tools for banks. Community banking groups and regulators' associations say small banks in particular need the free and accessible help.