The UKs financial services sector is failing to capture feedback from around 17 million customers, potentially breaching a regulatory requirement to show fair treatment of clients.
That is according to a study by market researcher Maru/edr, which found that less than half of financial services customers have been asked to give feedback in the last year.
This is despite the Financial Conduct Authority's (FCA) Treating Customers Fairly policy suggesting that feedback is one of the best ways to comply with the initiative.
The research also shows that around half of customers think they can be treated unfairly by providers, while less than a third rate the communications they receive highly.
"Customer feedback is vital for brands looking to protect and grow their market share," Maru/edr chief research officer, Steve Brockway, said.
"Yet for financial brands, customer feedback holds even more value in both improving services and demonstrating FCA compliance."
The findings are based on the responses of 1,000 independent customers who have held at least once financial product in the UK over the last 12 months.
They show that providers are failing to capture feedback despite 84% of customers saying they would be willing to take part in the research if given the opportunity.
Just 48% said that the communications they are sent from providers hold a relevant, personal appeal to them, and only 48% think they are receive enough engagement.
However, 70% of customers said that the communication they get from their existing finance provider is at least clear.
This marks a significant shift for the industry after the FCA three years ago urged finance firms to stop using excessively complicated language to reduce customer complaints.
"There's clearly an appetite from customers to have their voices heard - the growth of review sites is testament to the expanding feedback culture we now live in," Brockway continued.
"But financial services brands are clearly currently missing a huge opportunity, leaving customers feeling unfairly treated."