The Bank of Queensland made an unexpected announcement this week, saying it had discovered nearly ten years of mistakes in its sums, and would be refunding more than $34 million.

BOQ says ASIC has been informed of the mistakes, some of which date back to 2004, saying their overly-complex policies and large amount of manual processing lead to the indiscretions. The Bank also expects to incur additional costs from the refunds process, estimated around $11.5 million.

It has been an expensive reminder to the Bank of Queensland to simplify their processing protocols. The bank says up to 4 per cent of its customers have had errors made behind the scenes in their finances, which were first picked up in mortgage offset accounts last year.

News of  the announcement saw Bank of Queensland shares dip on Thursday.

BOQ CEO Stuart Grimshaw said: “We are not only addressing the underlying issues, but taking proactive steps to minimise future risks... this includes simplifying our product suite and improving our back office procedures, for example, through the automation of lending processes from origination through the to back office.”

The company was keen to save its reputation on the share market, their current stock value is available here.