Millions of Telstra customers are being impacted by an outage leaving them unable to make or receive calls.
The problem was first detected overnight but is continuing to affect users this morning.
Some customers are also reporting problems sending text messages.
Telstra insists that calls to Triple-Zero and mobile data aren’t affected.
The telco says it is working urgently to fix the issue.
“If customers are experiencing issues we recommend they switch airplane mode on and off or try making a data call using WiFi calling or other apps such as FaceTime,” Telstra posted on its website.
“We’re sorry for the late-night hassle for our customers.”
More to come.