The organisation representing volunteer firefighters says a budget blowout will not affect emergency callouts.
The United Fire Brigades Association has posted an interim loss of just under $450,000 for the year.
The association says a combination of poor accounting procedures, poor management and an over-ambitious programme is to blame for the deficit.
Its chief executive has resigned, but association chairman Peter Guard says no impropriety occurred.
Mr Guard says the association delivered increased services to its members and more firefighter competitions. These helped to improve skills, but came at a cost.
He says the accounting system failed to give early warning of looming financial difficulties.
The Fire Service, which has operational control of firefighters, has covered the deficit and is working closely with the association on a new business plan, Mr Guard says.