Delays are building at major airports around the country because of a system outage at international check-in points.
The Australian Border Force confirmed the service provider who manages the advanced passenger processing systems was experiencing an IT outage.
The issues are affecting all international check-in points across the major cities.
"We are working with the service provider to assist with resolving the matter urgently," a spokeswoman told AAP.
"The ABF will revert to manual processing of passengers where applicable."
It is understood Melbourne and Sydney airports are already experiencing some delays.