The publication of the latest figures marks one year since a national roll-out of the scheme began in May 2017.
The Banking Protocol enables bank branch staff to contact police if they suspect a customer is in the process of being scammed, with an immediate priority response to the branch.
Katy Worobec, managing director of economic crime at UK Finance, said: “Fraud can have a devastating impact on victims and is often targeted at the most vulnerable people in society, which is why we must work together to prevent it.
“The Banking Protocol shows how close cooperation between the industry and law enforcement can help to protect victims and crack down on fraudsters.”
UK Finance has led the development and implementation of the scheme, which is a partnership between the finance industry and police supported by National Trading Standards and the Joint Fraud Taskforce.
Branch staff, call handlers, police and trading standards officers in each area have all been trained in the steps that need to be taken when a customer is at risk.
The scheme was first introduced as a pilot in London during October 2016, before a national roll-out began in May 2017.
The most recent figures show that the scheme prevented more than £3m in fraud in the month of May alone with 17 arrests.
Detective Chief Superintendent Glenn Maleary, head of the City of London police’s economic crime directorate, said: “The scale and borderless nature of fraud means we are having to find new and innovative ways to protect the public and deter the criminals.
"Banks are often the first point of contact for someone who is about to fall victim to fraud, so the Banking Protocol is a vital way of protecting vulnerable victims and preventing fraudsters from taking advantage of them.
"Since it was initiated, the protocol has built its strength and though it is now preventing people losing millions of pounds to fraudsters, we have to remain vigilant to changing criminal trends and adapt accordingly.”
Mel Kenny, chartered financial planner for London-based Radcliffe & Newlands, said: “It is good to hear some success in protecting potential fraud victims.
"However, financial crime is still huge with victims losing out to simple but clever cybercrimes on a scale beyond control with many seemingly not worthy enough of investigation.”