Telstra blames ‘software defect’ for major outage that hit mobiles, trains and triple-zero calls
✓Telstra has blamed a “software defect” that changed the time servers for a major outage in which thousands of mobile customers were unable to make calls or access data on the country’s largest network on Wednesday morning.
The telco, which powers about 25m mobile services nationwide, confirmed the outage on Wednesday, with all services restored by 4pm AEST.
Telstra’s chief financial officer, Michael Ackland, who has been acting chief executive while Vicki Brady is on leave, said the outage began at 4.30am AEST, and was an intermittent issue affecting calls and data services.
He said there was no indication it was the result of malicious activity, but the company did not know exactly what caused the issue.
“The issue is impacting a number of nodes within our network that keep time across the mobile network,” Ackland told reporters.
“And when these nodes are not operating as expected, which is what has occurred, other parts of the network can be affected, resulting in intermittent issues with some mobile calls and data sessions.”
On Wednesday evening, Ackland provided more detail about the incident, saying a software fault had caused the GPS node to reset.
Telstra’s GPS node tells the rest of the organisation’s systems what the most accurate time is to the nanosecond.
The reset changed the time and synchronisation, which was then passed on to the rest of the Telstra network. An incorrect time can cause network problems including around authentication and data speeds.
“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 said. “We’ll update more of that once that investigation is complete.”
Ackland said the company acknowledged the outage “has been a big disruption to many people’s days. And we apologise for that.”
More than 7,500 customers reported the network disturbance on online monitoring platform Downdetector.
All of Victoria’s regional train services have been suspended as a result of radio network issues, which the operator said were caused by the Telstra outage.
Transport Victoria said V/Line services were “unable to operate” on Wednesday morning, with no estimated time for rectification. There was chaos at Southern Cross station on Wednesday evening with lengthy delays and commuters waiting in long lines for bus replacements.
V/Line customers were told to make their own way home and to avoid using the service on Thursday.
Some regional commuters in New South Wales were also facing disruptions after two train routes went down due to an “external telecommunication issue”, which the operator confirmed was the Telstra outage.
Transport NSW said trains were not running between Campbelltown and Moss Vale/Goulburn on the Southern Highlands line, and there were no trains running between Newcastle interchange and Maitland.
Replacement buses were being organised.
Telstra operates the triple-zero emergency call system, but it remained available for non-Telstra customers during the outage.
On Wednesday evening, Ackland revealed Telstra had conducted welfare checks on 333 people who attempted to call triple zero during the outage. Of those, 238 said they didn’t need assistance. The remainder were referred to state and territory police for welfare checks. Six customers said they needed assistance, which was provided immediately, Ackland said.
Some triple-zero calls were able to successfully switch to TPG and Optus mobile networks.
He said the volume of calls to triple zero was higher than expected, which may have been due to people calling triple zero to test it during the outage.
after newsletter promotion
In a statement, the communications minister, Anika Wells, and the emergency management minister, Kristy McBain, said the Triple Zero Custodian reported that 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,” Wells and McBain said.
“However, the Triple Zero Custodian has advised that some callers were unable to connect to the ECP, and that these are being investigated by Telstra.”
They said the Australian Communications and Media Authority will conduct an investigation into the outages.
WA police said the Telstra outage was affecting calls to triple zero and advised people to offer support to vulnerable family members.
Eftpos systems were also taken offline during the outage, affecting taxi payments in NSW and in retail environments, according to providers Commonwealth Bank and Tyro.
The prime minister, Anthony Albanese, said the outage was “deeply concerning”.
“It’s very disruptive to people’s lives throughout the country,” he said.
“Some people have been unaffected, but many have been severely disrupted. Telstra are investigating but we’re working closely with them.”
The opposition leader, Angus Taylor, demanded the government “front up” and explain the outage to Australians.
Taylor called on Wells to provide an explanation.
“The government needs to explain what has gone on here, why has this happened, what they’re going to do to make sure it’s fixed and never happens again,” Taylor said.
Ackland said Wednesday’s outage was not the result of a cyber-attack, but warned the company had received reports 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 comes after other telecommunications giants Vodafone and Optus experienced problems.
In June, Vodafone customers were left with intermittent reception and data issues across Australia.
Two deaths have been linked to an outage at Optus in September 2025, which lasted almost 14 hours and affected hundreds of calls in four states and territories.
New rules were handed down by the Australian Communications and Media Authority in March requiring telcos to publish when an outage started and when it was restored in detail, as well as the cause.
Read the full story at BBC ↗ · The Guardian ↗
Australia's largest telecommunications company, Telstra, experienced a network outage beginning at 4:30am AEST on Wednesday. A software defect caused the GPS node—which synchronises time across the mobile network to nanosecond precision—to reset. This incorrect time synchronisation cascaded through network systems, affecting authentication and data speeds, and caused intermittent disruptions to mobile calls and data services for thousands of customers across the country. The outage was not a result of malicious activity. Regional train services in Victoria and NSW were suspended because they rely on Telstra's radio network. Some emergency triple-zero calls could not connect initially, though the core system remained operational and calls successfully switched to alternative carriers for some users. EFTPOS systems also went offline in some retail and taxi environments. Telstra restored all services by 4pm and confirmed no deaths resulted from the outage. The company is investigating the root cause and acknowledged responsibility for fixing the underlying process failure.
Read the full story at BBC ↗ · The Guardian ↗
Telstra has blamed a “software defect” that changed the time servers for a major outage in which thousands of mobile customers were unable to make calls or access data on the country’s largest network on Wednesday morning.
The telco, which powers about 25m mobile services nationwide, confirmed the outage on Wednesday, with all services restored by 4pm AEST.
Telstra’s chief financial officer, Michael Ackland, who has been acting chief executive while Vicki Brady is on leave, said the outage began at 4.30am AEST, and was an intermittent issue affecting calls and data services.
He said there was no indication it was the result of malicious activity, but the company did not know exactly what caused the issue.
“The issue is impacting a number of nodes within our network that keep time across the mobile network,” Ackland told reporters.
“And when these nodes are not operating as expected, which is what has occurred, other parts of the network can be affected, resulting in intermittent issues with some mobile calls and data sessions.”
On Wednesday evening, Ackland provided more detail about the incident, saying a software fault had caused the GPS node to reset.
Telstra’s GPS node tells the rest of the organisation’s systems what the most accurate time is to the nanosecond.
The reset changed the time and synchronisation, which was then passed on to the rest of the Telstra network. An incorrect time can cause network problems including around authentication and data speeds.
“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 said. “We’ll update more of that once that investigation is complete.”
Ackland said the company acknowledged the outage “has been a big disruption to many people’s days. And we apologise for that.”
More than 7,500 customers reported the network disturbance on online monitoring platform Downdetector.
All of Victoria’s regional train services have been suspended as a result of radio network issues, which the operator said were caused by the Telstra outage.
Transport Victoria said V/Line services were “unable to operate” on Wednesday morning, with no estimated time for rectification. There was chaos at Southern Cross station on Wednesday evening with lengthy delays and commuters waiting in long lines for bus replacements.
V/Line customers were told to make their own way home and to avoid using the service on Thursday.
Some regional commuters in New South Wales were also facing disruptions after two train routes went down due to an “external telecommunication issue”, which the operator confirmed was the Telstra outage.
Transport NSW said trains were not running between Campbelltown and Moss Vale/Goulburn on the Southern Highlands line, and there were no trains running between Newcastle interchange and Maitland.
Replacement buses were being organised.
Telstra operates the triple-zero emergency call system, but it remained available for non-Telstra customers during the outage.
On Wednesday evening, Ackland revealed Telstra had conducted welfare checks on 333 people who attempted to call triple zero during the outage. Of those, 238 said they didn’t need assistance. The remainder were referred to state and territory police for welfare checks. Six customers said they needed assistance, which was provided immediately, Ackland said.
Some triple-zero calls were able to successfully switch to TPG and Optus mobile networks.
He said the volume of calls to triple zero was higher than expected, which may have been due to people calling triple zero to test it during the outage.
after newsletter promotion
In a statement, the communications minister, Anika Wells, and the emergency management minister, Kristy McBain, said the Triple Zero Custodian reported that 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,” Wells and McBain said.
“However, the Triple Zero Custodian has advised that some callers were unable to connect to the ECP, and that these are being investigated by Telstra.”
They said the Australian Communications and Media Authority will conduct an investigation into the outages.
WA police said the Telstra outage was affecting calls to triple zero and advised people to offer support to vulnerable family members.
Eftpos systems were also taken offline during the outage, affecting taxi payments in NSW and in retail environments, according to providers Commonwealth Bank and Tyro.
The prime minister, Anthony Albanese, said the outage was “deeply concerning”.
“It’s very disruptive to people’s lives throughout the country,” he said.
“Some people have been unaffected, but many have been severely disrupted. Telstra are investigating but we’re working closely with them.”
The opposition leader, Angus Taylor, demanded the government “front up” and explain the outage to Australians.
Taylor called on Wells to provide an explanation.
“The government needs to explain what has gone on here, why has this happened, what they’re going to do to make sure it’s fixed and never happens again,” Taylor said.
Ackland said Wednesday’s outage was not the result of a cyber-attack, but warned the company had received reports 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 comes after other telecommunications giants Vodafone and Optus experienced problems.
In June, Vodafone customers were left with intermittent reception and data issues across Australia.
Two deaths have been linked to an outage at Optus in September 2025, which lasted almost 14 hours and affected hundreds of calls in four states and territories.
New rules were handed down by the Australian Communications and Media Authority in March requiring telcos to publish when an outage started and when it was restored in detail, as well as the cause.
Read the full story at BBC ↗ · The Guardian ↗
Telstra operates approximately 25 million mobile services nationwide The outage began at 4:30am AEST on Wednesday A software defect caused the GPS node to reset The GPS node synchronises time across the network to nanosecond precision All services were restored by 4pm AEST The outage caused intermittent issues with mobile calls and data sessions The outage was not the result of malicious activity More than 7,500 customers reported the outage on Downdetector Victoria's regional train services were suspended due to radio network issues caused by the Telstra outage Train services were disrupted in NSW between Campbelltown and Moss Vale/Goulburn, and between Newcastle interchange and Maitland Telstra operates the triple-zero emergency call system Some emergency calls were unable to connect during the outage Telstra conducted welfare checks on 333 people who called triple-zero during the outage Of the 333 welfare checks, 238 people said they did not need assistance and six needed immediate assistance No deaths resulted from the outage EFTPOS systems went offline in NSW retail and taxi environments The Australian Communications and Media Authority will conduct an investigation The outage was 'deeply concerning' and 'very disruptive' The government needs to explain what happened and prevent future occurrences The higher-than-expected volume of triple-zero calls may have been due to people testing the service
Read the full story at BBC ↗ · The Guardian ↗
- Telstra's network outage on Wednesday morning affected approximately 25 million mobile customers nationwide, caused by a software defect that reset the GPS time server
- The outage disrupted train services in Victoria and NSW, emergency triple-zero calls, and EFTPOS payments; all Telstra services were restored by 4pm AEST
- Telstra conducted welfare checks on 333 people who called triple-zero during the outage; six required immediate assistance and none died as a result