West Bromwich Building Society is using anti-money-laundering software to improve security and meet Financial Services Authority regulations.
The building society has installed STB-Detector throughout its 50 branches. The software, from STB Systems, checks automatically for any suspicious activity or transactions in accounts.
The building society previously relied on manual scrutiny of crude data extracts - for example, recent transactions of over £10,000 - to protect against fraud and money laundering.
It moved to an automated approach after similar sized businesses were fined for failing to comply with the FSA's "Know your customer" rules, said West Bromwich Building Society information security manager Rob Hine.
STB-Detector compares transactions with a history of individual account activities and uses this information to highlight unusual movements on accounts.
Hine said, "The benefit of STB-Detector is it can look back at the behaviour of a customer. It shows the behaviour change. We have put four years' of customer transactions into the system, so it has got enough data."
The automated system produces a manageable number of alerts, whereas the old system involved checking thousands of transactions that met basic selection criteria, said Hine.
"The rules within the STB system are user-configurable and we could improve how we manage referrals to the National Criminal Intelligence Service," he added.
"We could load into the system our historic database of referrals - a Microsoft Access database with 100Mbytes of data - and have an improved case management and audit trail."
User configuration allows the building society to define the sort of behaviour the system will highlight, whether that is transactions over £50,000, cash transactions or transactions that are five times higher than usual for a customer, said Hine.
"We have also got the system linked to our intranet, improving the process of staff making manual referrals," he added.