"FIS is participating with the CFPB in their overdraft market study," FIS said in a statement. "FIS has anonymized all of the data we have provided with the CFPB."

In a recent letter to Richard Cordray, director of the CFPB, CUNA President/CEO Jim Nussle wrote: "I urge you to take into consideration the importance of overdraft programs to consumers who do not want to be embarrassed at the point of sale and want the confidence of knowing a purchase or transaction, such as a mortgage payment, will be honored."

Nussle also expressed concern about imposing another unplanned cost burden on credit unions.

Ryan Donovan, chief advocacy officer for CUNA, shared his concern that the costs of the data collection might trickle down to credit unions.

"Overdraft protection is a very important issue to credit unions because it allows them to meet a need that their members have," Donovan said. "Most credit unions have overdraft protection programs because it is something their members want and need. What we are to do through this regulatory process is to make sure that once the CFPB is through its rule-making that credit unions are able to offer this valuable product to their members."

The ABA expressed related concerns, as well as questions about the CFPB's authority for such a request, in a memo to state associations from Virginia O'Neill, senior vice president and director of the Center for Regulatory Compliance, and Jonathan Thessin, senior counsel II.

"The order demonstrates the dangers of the authority provided to the Bureau by Section 1022 of the Dodd-Frank Act," the memo read. "That section grants the Bureau overly broad authority to request virtually any information from any company that offers a financial product or service, or acts as a service provider to financial companies, like Fiserv, FIS and Jack Henry. The Bureau's order raises serious questions about Section 1022, including issues of due process, appropriate limitations, who bears the costs, and perhaps even constitutional matters. This example certainly makes clear that Congress must reform this provision."

It went on to read: "The data request will require Fiserv to expend 'thousands of hours' of employee time, according to a statement Fiserv recently released. Inevitably, all three core processors will pass the costs of responding to the 1022 order on to their client financial institutions, resulting in higher fees for consumers."

Donovan said it's not unusual for CUNA and the ABA to side on a particular issue.

"On regulatory burdens if it affects our member institutions similarly, we will in all likelihood take the same or very similar positions," he said.

NAFCU also issued a statement opposing the CFPB's order, calling its effort on overdraft data "regulatory overreach."

"The CFPB's continued pursuit of data on overdraft programs constitutes extraordinary regulatory overreach," Alicia Nealon, director of regulatory affairs for NAFCU, said. "Moreover, NAFCU is extremely concerned that the costs of the Bureau's wide-sweeping fishing expedition are going to trickle down to credit unions, as core processors, like Fiserv, will likely need to recoup the costs of complying with the orders. Credit unions should not have to foot the bill for the CFPB's discretionary activities, as they are already expending considerable resources to comply with the Bureau's myriad new regulations."

Nealon added, "Credit unions are focused on providing value to their members by offering responsible overdraft protection. Indeed, NAFCU's November 2014 Economic & CU Monitor survey found that every respondent offered an alternative to overdraft or courtesy pay programs, with overdraft lines of credit and linked savings or money market accounts being the most popular (82.9% each). Additionally, 91.2% of respondents reverse overdraft charges on a case-by-case basis."