A CUNA survey of some of its member credit unions suggests credit unions with less than $10 billion in assets have begun to take a hit to their debit card interchange even though they were not supposed to feel the impact of a debit interchange cap.

Passed as part of the Dodd-Frank financial reform act, the so-called Durbin Amendment, named for its chief sponsor Illinois Senator Richard Durbin (D), capped interchange for debit card issuers with more than $10 billion in assets, but was supposed to exempt debit card issuers of fewer than $10 billion. Only four credit unions have assets of more than $10 billion and thus have their debit interchange capped by the rule, though several others seem likely to pass that threshold this year.

To help facilitate the exemption, the large card brands and card processors widely implemented a two tier interchange schedule which set one payment rate for institutions which are covered by the cap and another for institution, largely community banks and most credit unions, which are not.