Telstra outage disrupts mobile services across Australia
Telstra has attributed a major outage on Wednesday to a "software defect" that altered time servers, leaving thousands of mobile customers unable to make calls or access data on the country's largest network. The telco, which supports approximately 25 million mobile services nationwide, confirmed the outage began at 4:30am AEST, with all services restored by 4pm AEST.
Michael Ackland, Telstra's chief financial officer and acting chief executive while Vicki Brady is on leave, stated that the issue was intermittent and affected calls and data services. He emphasized that there was no evidence of malicious activity, though the exact cause was initially unclear.
Software defect disrupts network time synchronisation
Ackland explained that the outage impacted nodes in the network responsible for maintaining time across the mobile network. "When these nodes are not operating as expected, other parts of the network can be affected, resulting in intermittent issues with some mobile calls and data sessions," he told reporters. Later that evening, he provided further details, revealing that a software fault caused the GPS node to reset. This node provides precise time to the nanosecond for the entire network. The reset altered the time and synchronisation, which propagated through the system, leading to authentication and data speed problems.
Ackland acknowledged the disruption, saying, "The fact that it occurred means that there is something in our process that we need to fix, and we change, and we are working through that." He apologised for the inconvenience, noting that over 7,500 customers reported the issue on Downdetector.
Commuter chaos as train services suspended
The outage caused significant transport disruptions. All regional V/Line train services in Victoria were suspended due to radio network issues linked to the Telstra outage. Transport Victoria stated that V/Line services were "unable to operate" on Wednesday morning, with no estimated restoration time. At Southern Cross station, lengthy delays and long queues for bus replacements were reported. V/Line customers were advised to make alternative arrangements and avoid using the service on Thursday.
In New South Wales, two train routes experienced disruptions due to an "external telecommunication issue," confirmed as the Telstra outage. Trains between Campbelltown and Moss Vale/Goulburn on the Southern Highlands line, and between Newcastle interchange and Maitland, were suspended. Replacement buses were organised.
Triple-zero welfare checks conducted
Telstra operates the triple-zero emergency call system, which remained available for non-Telstra customers during the outage. Ackland revealed that welfare checks were conducted on 333 people who attempted to call triple zero during the outage. Of these, 238 said they did not need assistance, while the remainder were referred to state and territory police for welfare checks. Six customers required immediate assistance, which was provided. Some triple-zero calls successfully switched to TPG and Optus networks.
Communications Minister Anika Wells and Emergency Management Minister Kristy McBain stated that the Triple Zero Custodian reported some emergency calls did not connect. "The core triple-zero system remains operational, with connected calls flowing as expected from carrier networks to the Emergency Call Person (ECP), and on to state and territory emergency services dispatchers," they said. However, they noted that some callers were unable to connect to the ECP, and these are being investigated by Telstra. The Australian Communications and Media Authority (ACMA) will conduct an investigation.
WA police reported that the outage affected calls to triple zero and advised people to support vulnerable family members. Eftpos systems were also offline, affecting taxi payments in NSW and retail environments, according to Commonwealth Bank and Tyro.
Political reactions and scam warnings
Prime Minister Anthony Albanese described the outage as "deeply concerning" and "very disruptive to people's lives throughout the country." Opposition Leader Angus Taylor demanded the government explain the outage to Australians, calling on Minister Wells to provide an explanation.
Ackland warned of scammers calling people claiming to be from Telstra. "Our advice to our customers is, if you get a call from someone claiming to be Telstra asking you for details in light of today's outage, please hang up and call us back directly," he said.
The Telstra outage follows similar incidents at Vodafone in June and Optus in September 2025, the latter of which lasted nearly 14 hours and was linked to two deaths. In March, ACMA introduced new rules requiring telcos to publish details of outages, including start and restoration times and causes.
