July 19: A raft of Australian institutions – including major banks, media outlets and an airline – have reported being hit by a mass IT outage.

Jetstar has been crippled at Sydney airport, supermarkets are experiencing checkout chaos, and broadcast networks have been left scrambling on air as autocue and graphics failed.

Hours before Australia was severely affected, a handful of airlines in the US also reported having to ground planes due to IT issues.

The cause of the outage is unclear, but many of those affected have linked it to Microsoft PC operating systems.

Australian outage website Downdetector shows issues being reported by the National Australia Bank, telecom firm Telstra, Google and more.

An official Microsoft 365 service update posted to X earlier in the day said “We’re investigating an issue impacting users ability to access various Microsoft 365 apps and services”.

US airlines issue global ground stop on all flights

United, Delta and American Airlines – which are all based in the United States – have issued a “global ground stop” on all of their flights.

Flights that are currently airborne will continue, but no further flights will take off for now.