Telstra is beginning to restore mobile services across the country after a massive outage that wreaked havoc on customers using their mobile phones and internet.
Scores of customers have taken to social media to vent their frustration about problems accessing the telco's mobile and data networks from about 6.30pm (AEDT) on Thursday.
Many experienced problems making and receiving calls and have been unable to access their digital data service.
Coverage has been dropping in and out throughout the evening.
Telstra said the cause of the outage was still unknown.
"We are progressively restoring mobile services and we anticipate returning to normal soon," the telco said at about 9pm.
"The cause of the incident is yet to be determined but at this early stage we understand we have had a problem with the part of the network that allows phones to register and therefore make calls and use data.
"We apologise to our customers for the inconvenience caused."
The outage follows a similar major disruption in February which the company blamed on human error.
