The Federal Reserve is under increasing pressure to provide clarity on whether nonbank fintech firms that receive a special federal charter will have direct access to central bank lending and to the U.S. payment systems.

The Office of the Comptroller of the Currency confirmed in July that it would accept applications from fintech firms for a "special-purpose" national bank charter, although the new license has been legally challenged by state regulators.

But many experts say the OCC's charter would lose value if the Fed did not allow direct entry to fintech firms. Those firms now, for example, can access the payments system only through bank partners.

During early discussions about the OCC charter, a decision by the central bank about allowing fintech firms into the payments system or to become a Fed member "may have been on the back-burner but was certainly on the stove," said former Comptroller of the Currency Thomas Curry, who had initiated the charter plan while at the agency.

Read more in American Banker.