The problems are piling up for budget carrier Jetstar.
An IT outage forced the airline to cancel dozens of flights just ahead of a planned strike by airline staff including pilots.
More than 30 Jetstar flights were cancelled with the airline issuing an apology and promising refunds or free ticket changes.
This could put extra pressure on capacity over the next few days before planned strikes begin at the weekend.
The airline has said customers can bring their flights forward to avoid possible disruption at the weekend and into next week as ground crew and pilots start separate strikes in Sydney, Melbourne, Avalon, Brisbane, Cairns and Adelaide.
"We understand this industrial action creates uncertainty, and so if you are travelling with us between 14 and 20 December and you would like to cancel your travel now, you can request a refund by contacting us on live chat," the airline said.
"Passengers can also contact us to move their flight forward to travel between now and 13 December at no additional cost."
Ground crews and pilots are striking over improved pay and working conditions.
The Transport Workers Union is seeking a 4% pay increase, more rest breaks, 12-hour breaks between shifts, and a guaranteed 30 hours work a week.
