Bank of Queensland expects to book a $175 million expense from bad loans, mostly due to COVID-19, for the full year.

The pre-tax figure will include $133 million attributed to the economic impact of the pandemic after some borrowers lost work and struggled to make repayments.

The bank had set aside $10 million in the first half of fiscal 2020 and $123 million for the second half.

The estimates were based on economic forecasts and assumed higher unemployment, lower property prices and an extended economic downturn.

The bank said it was helping customers who are struggling.

Some 12 per cent of housing loan customers and 16 per cent of small and medium-sized business customers were on support arrangements as of August 31.

Also impacting the full-year results will be an $11 million pre-tax expense of related to historical employee pay and superannuation obligations.

The results, for the full-year to August 31, are due on October 14.

The bank’s shares were trading down 3.86 per cent at $6.10 at 1151 AEST.