WASHINGTON — An expanded database of complaints that consumers have filed against large financial institutions went public Thursday, but the debate over whether the new treasure trove of information helps or hurt banks is just beginning.

On one hand supporters of the Consumer Financial Protection Bureau's online complaint portal, which grew nearly fivefold Thursday, say the database is already making institutions more sensitive to consumers and efficient in responding to complaints. But others complain that some banks do not deserve the obvious reputational risk from public information — much of which has not been verified — about their quality of customer service.

"There's a need to know what you're dealing with but to name names is a concern regarding reputational risk [for financial companies] which is something the bureau doesn't seem to be fully sensitized to," Donald Lampe, a partner at the Dykema law firm, said in an interview. "There's no indicator whether the data has been normalized to look at incidents and determine what are the serious and actionable incidents."

The database, which was mandated under the Dodd-Frank Act and launched in June as a beta version, has now expanded from about 19,000 complaints dealing mostly with credit card issues to a huge archive of now 90,000 individual complaints across most credit-related sectors. Each item includes details down to the company involved, how it responded and in what timeframe.

CFPB officials say the expanded portal — which applies to banks and certain nonbanks that have at least $10 billion in assets — will help guide regulatory policy.

Consumer complaints "are a source of information that we consult in approaching our supervisory work of examining financial institutions," CFPB Director Richard Cordray said Thursday in Des Moines, Iowa, at a CFPB-sponsored field hearing about the database.

But even bankers themselves note the database offers another advantage: providing more motivation to institutions to respond promptly and sufficiently to resolve complaints.

"The consumer complaint process is something we take very seriously," Carl E. Spradlin Jr., Comerica's compliance risk manager, said at the field hearing. "The consumer complaint database portal is a good method for transparency for our customers and overall accountability."

After receiving a complaint from a customer, the CFPB will include it in the database either after the company has responded or 15 days after it was submitted — whichever comes first. Once posted on the portal for public view, the information can be downloaded for data manipulation.

Although it is difficult to rank institutions by the number of complaints filed against them, the database does allow easier ranking of complaints by product types. As of March 22, over 55% of the complaints in the database were related to mortgage issues, which was the most represented sector. Credit cards came in second at 21.5% followed by bank accounts or other bank services (16.7%), student loans (3.8%) and consumer loans (2.8%).

But the public identification of companies involved in the complaint process is drawing concerns, partly because the portal only includes complaints submitted against larger institutions. (The CFPB will refer complaints about smaller institutions to other regulators.)

The database "is unfairly targeting some institutions and not others," David Pommerehn, counsel of legislative and regulatory affairs at the Consumer Bankers Association, said at the field hearing. "If the bureau's intention is to publicly release names to help consumers better shop in the financial market, it would give institutions under $10 billion [in assets] an unfair advantage as they are not being listed in the database."

Meanwhile, Richard Hunt, the CBA's chief executive, said he is less concerned about the "headline risk" institutions face from the database than he is about the fact that the CFPB will not verify all of the information about a complaint before it is posted.

"It may provide a risk to banks, but that's life. It's been mandated by Dodd-Frank, and that's the business were in — to take risk," Hunt said in an interview. "We're not trying to prohibit information from going out to the public. We're just trying to prohibit inaccurate information from going to the public."

Cordray acknowledged that even though the agency does go to some length to verify that the customer filing a complaint in fact has a relationship with the institution, it has not confirmed the accuracy of all the data.

"While we do not verify each and every allegation that consumers make in their complaints, we do verify that a commercial relationship exists between that consumer and the named company," he said. "The complaint only gets uploaded onto the database after the company verifies that the consumer is in fact its consumer."

Lampe said because the complaints can easily be analyzed and companies can be identified by manipulating certain data points, consumer lawyers will be able to use the database to help fight civil actions.

"There's thousands upon thousands of foreclosure defense cases where an attorney is looking to portray a company in a bad light and they can say this particular servicer had 7,000 complaints filed against them at the federal agency," he said.

Jo Ann Barefoot, chair at Treliant Risk Advisors, said the expanded database is "a mixed picture" for the industry.

"There is certainly a risk in creating such an accessible and easy-to-manipulate database," she said. "And the fact that the CFPB seems to be putting this data out there in a way that it can be utilized by such a broad array of players is revolutionary, but it also poses risks.

"Some of the kinds of things that people are complaining about may not be as serious as they sound from just looking at the database."

But she added that there also advantages. "This will help the industry actively manage their responses to complaints and banks will continue their efforts to build more robust complaint database systems of their own," Barefoot said. "This will make banks with low levels of complaints look good by comparison."

Others said the benefits of the portal outweigh the risks.

John Taylor, the head of the National Consumer Reinvestment Coalition, said a consumer will tend to make a decision about a company's reputation based on what happens directly to that person, not what a database reveals about others' experiences.

Taylor said he believes the database is leading to faster and better responses. He recalled how he filed a complaint with the CFPB against Barclays after he spent nearly six months trying to resolve fraudulent activity on his account.

"I finally went online and filed a complaint with the CFPB and within one week, the bank restored all my funds," Taylor said.

Indeed, Lampe agreed that the database indicates a strong overall response record by the industry. "This report does not show that the industry was non-responsive," he said. "In almost every one of the 90,000 cases it shows that companies responded on time and that the relief was satisfactory to all sides."

Meanwhile, policymakers besides just officials at the CFPB said the portal can help guide the direction of enforcement actions.

"The more we know about consumer complaints the more we can find patterns and direct really efficient and wise enforcement," said Iowa Attorney General Tom Miller at the field hearing. "We all will be more intelligently able to enforce compliance."