The plaintiff in the case originally filed a class-action suit in District Court back in late 2015, alleging, among other things, that the credit union breached its account agreements by using the available balance method instead of the ledger balance method when determining when to impose overdraft fees.

Then in November 2017, a District Court judge dismissed the case against LGE Community, which has $1.2 billion in assets and about 107,000 members. The plaintiff later appealed, however, which brought the case back to court and has prompted involvement from the Georgia Credit Union League, CUNA and NAFCU.

Among other things, the trade groups emphasized in their amicus brief that LGE Community's disclosures as well as Regulation E's overdraft opt-in rules and model consent form protected the credit union.

"The LGE account agreement (like most credit-union member agreements) makes clear that overdrafts are determined on the basis of 'available' funds," it argued. "The district court also properly dismissed plaintiff's claim that LGE violated the [Electronic Fund Transfer Act] EFTA by using the Model Form to opt its members in to an overdraft service that assesses fees based on the available balance."

The groups also said the court should not punish financial institutions for using a form that the federal government enacted for their protection.

"Even if the language of the Model Form were unclear (and it is not), liability cannot and should not be imposed against credit unions and other financial institutions that relied on the form in good faith," it said.

The groups also argued that LGE Community's use of the available balance method for determining when to impose overdraft fees was correct.

"Like the [Federal Reserve] Board, the CFPB has also expressly acknowledged that available balance is a common and acceptable method for assessing overdrafts. That, coupled with the fact that the CFPB did not change the 'enough money' language when issuing its new 'prototype' Model A-9 Forms, demonstrates the federal agency's understanding that 'enough money' covers fees based on the available balance," they said.

At least 40 credit unions and banks have been hit with similar class-action suits regarding their overdraft practices, the brief said.

"Our brief identifies crucial regulatory history as well as a critical due process argument," CUNA Senior Director of Advocacy and Counsel Leah Dempsey said. "CUNA's assistance is particularly warranted in light of the fact that this is the first federal appellate court to consider the issues presented. And, many credit unions are facing 'gotcha' litigation on this issue based on highly technical alleged violations."