A new audit report says Defence has been getting on with the job of providing emergency disaster relief but it hasn’t actually counted the cost.

As flames lick at homes or floodwaters lap front doors, people look to the heavens for help – and then the army arrives and gets on with the job.

But at what cost?

Defence really doesn’t know, but the Australian National Audit Office (ANAO) says maybe it should.

For years Defence hasn’t properly completed all the required paperwork.

“The main focus of Defence units has been to complete tasks and they have not prioritised reporting on tasks outside of the service chain of command,” a new audit report says.

Otherwise, the audit concluded that Defence procedures for what’s known as Defence Assistance to the Civil Community (DACC) are generally effective.

This work is becoming more common. Defence says it conducted 275 emergency DACC tasks between 2005/06 and 2012/13.

That includes major disasters such as Victoria’s bushfires in 2009 and Queensland’s Cyclone Yasi in 2011 and smaller incidents where local base commanders provided personnel to help local authorities.

Disaster response is primarily a responsibility of states and territories who may request Commonwealth assistance.

When given the go-ahead, Defence has shown it can respond speedily and effectively.

Defence says this doesn’t cost that much, as it mostly involves provision of personnel. Generally it will absorb costs under $10 million and seek government supplementation for higher costs.

The ANAO said Defence had no real understanding of its costs in terms of emergencies.

“DACC has been largely focused on response efforts, with less attention given to meeting the administrative requirements set out in the DACC Manual, particularly in the areas of task recordkeeping and cost recovery,” it said.

The DACC Manual specifies that costs be recovered for assistance for post-disaster recovery but Defence mostly hasn’t bothered.

It does plan to revise the manual to indicate that costs generally aren’t recovered unless by prior agreement.

Defence agreed to do better at reporting on its DACC tasks.