A fire at Telstra's Chatswood exchange has plunged users into the dark ages, with widespread outages on Thursday affecting calls and text messages as well as delaying flights.
Telstra confirmed services were being affected around midday on Thursday, saying: "A fire at the Chatswood Exchange in Sydney this afternoon has been contained, but damage has been caused to some power infrastructure.
"As a result a number customers are experiencing loss of service."
Telstra also said any text messages affected by the outage were being held, and some may have been sent "incorrectly".
"As a result of the Chatswood Exchange fire today its possible some SMS messages have been incorrectly delivered," a statement sent to HuffPost Australia said.
"Customers won't be receiving SMS messages in the short term while we resolve this issue."
In terms of the breadth of the outages, a Telstra spokesperson could not confirm how many people were affected other than saying "we've had reports customers affected in different parts of the country".
Jetstar Airways flights were also affected by the outage, as Telstra systems are used in check-in processes.
A Jetstar statement said flights in Melbourne and Sydney were delayed but services were coming back online about 3.30pm.