By Kim Lyell ABC News 9th October 2012
The Bank of Queensland (BOQ) is set to pay back about $15 million it has overcharged borrowers.
BOQ chief executive officer Stuart Grimshaw says an operational error has affected borrowers with a mortgage offset account for the past decade.
Mr Grimshaw says the glitch impacted about 6,500 customers, who will be repaid the money owed, plus interest.
"This goes back a number of years so we've got a lot of people looking through it and calculating interest on the loans," he said.
"Not only the loans that are still with us, but those loans that have been paid out and gone, so it's a big body of work that we have undertaken.
"But we have done the right thing in getting on top of it and as soon as we found out about it, letting everyone know."
The bank posted a first-half loss this financial year, but Mr Grimshaw said he expected a second-half profit.