Optus users were unable to make or receive any phone calls as the network experienced a major outage.
The telecommunications giant announced the problem causing the network-wide outage had been fixed on Tuesday afternoon.
Customers woke to find their services interrupted about 7am Tuesday, with messages saying their phone had been “disconnected” when trying to make calls.
However, shortly before 1pm the matter had been resolved.
“This morning, some Optus voice and fixed customers may have experienced issues due to a network outage,” the company said in a statement.
“The fault was a priority for our team and the technical issue impacting customers has now been successfully resolved.
“We sincerely apologise to customers for any inconvenience and thank them for their patience while affected services were restored.”
Earlier, customers who went to the Optus website found their phones not working was the result of the “major outage”.
While thousands of users were left unable to make voice calls, some NBN landline customers were also been affected by the outage.
The outage began at 7am and Optus did not put a time frame on when it was due to be completed, but it was resolved under six hours later.
It is not known what caused the outage which left customers frustrated.
“We’re aware of an issue impacting some Optus mobile customers’ ability to make voice calls,” the company said in a tweet on Tuesday morning.
“We are investigating and working to restore services as a priority. We understand connectivity is important and apologise for any inconvenience caused.”
An Optus spokesperson said the teams had identified the fault just before 11am.
“Our teams have identified the fault and restoration of voice services for impacted customers is underway,” the spokesperson said.
“We apologise to impacted customers and thank them for their patience while the remaining affected services are restored.”
Multiple Optus users took to social media when they realised their phones were not working.
While they cannot make any phone calls, texts appear to be working.
One man said his friends and family reported that his phone was “disconnected”.
Another said they only had success in calling other people on the Optus network.
“Why are all my calls saying the number has been disconnected?” one Twitter user wrote.
Rival company Telstra issued a statement saying it had not suffered from any network problems.
“An Optus network issue is currently affecting calls to and from their customers, which means you may have trouble getting through to those on the Optus network,” Telstra said in a tweet.
“We’ve checked and there are no issues with our network. We’re working with Optus to get everyone reconnected.”
