A computer problem disrupted the travel plans of thousands of Virgin Blue passengers on Sunday, stranding them at airports around Australia.
Virgin Blue spokesman Colin Lippiatt said some domestic and international flights had to be cancelled and others faced long delays.
He said extra staff were being brought in to help manually check-in passengers, but it is a slow process.
The ABC reports investigations are underway into what went wrong.
About 800 Virgin passengers were stuck at the Brisbane domestic terminal as all of the airline's domestic and international flights were delayed.
Adelaide passengers were also been affected by the failure.
The delays in Australia are having a flow-on affect in New Zealand where several Virgin Blue flights to and from Australia have been delayed or rescheduled.