Telstra Blames Software Defect After Nationwide Outage Hits Triple-Zero Calls and Trains

Telstra has had to run hundreds of welfare checks on customers after an hours-long national outage on Wednesday knocked out services ranging from mobile phones to regional trains — and left some Australians unable to reach triple zero.

The telco apologised, saying it was "so sorry", and pointed to a software defect as the cause. The disruption began in the early morning and, according to the company, was fully resolved by 4pm on Wednesday. Tens of thousands of people reported problems with mobile signal and internet, and the prime minister moved to hose down speculation that anything malicious was behind it.

Communications Minister Anika Wells confirmed that some Telstra users could not get through to triple zero, while train networks and card payment systems around the country were badly affected. Victoria's entire regional rail network came to a standstill, and some regional and intercity services in NSW ran with significant delays.

Telstra chief financial officer Michael Ackland said the company was still investigating but was confident its teams had found and isolated the faulty software. He also revealed that the potential triple-zero problems were broader than first believed. By Wednesday afternoon, Telstra had carried out 333 welfare checks on customers whose emergency calls had failed or dropped out after connecting.

"The volume of these welfare checks was higher than we expected and it has prompted us to investigate further," Ackland said. On the root cause, he added: "The fact that it occurred means that there is something in our process that we need to fix and to change - we are working through that."

Wells drew a distinction between this incident and earlier failures, including an Optus outage in September that was linked to multiple deaths. "This is not a triple zero outage," she said. "This is a Telstra retail outage that has affected their customers right across the country." She called the EFTPOS failures hitting small businesses "incredibly frustrating". Emergency Management Minister Kristy McBain noted that Australian phones must fall back to other networks for triple-zero access.

Reports of trouble started appearing on the outage-tracking site DownDetector at about 4.30am. Telstra earlier described the fault as a node problem affecting timekeeping across its network, producing intermittent outages, with the source traced to servers in Sydney and Melbourne data centres. "Time synchronisation in those nodes wasn't working as it should. We don't know why," Ackland said.

In a statement, the company said: "We know how much our customers rely on our network and understand just how much of a disruption this is to your day. For that we're so sorry." Ackland estimated as many as "tens of thousands" of people could be affected, though likely fewer — while online reports suggested the true scale could be considerably bigger than Telstra's account. In its 2025 annual report, the company said it provides around 24.9 million retail mobile services plus 3.4 million consumer and small-business bundle, data and voice-only services.

Police in Victoria, NSW and Western Australia acknowledged the interruption could pose an issue, though those forces said there was no evidence frontline staff were affected or that their own networks were disrupted. Ackland said Telstra was checking whether emergency services were hit but considered it unlikely, since they run on a different network. Wells said the Australian Communications and Media Authority (ACMA) would conduct "a full investigation", adding: "Telstra will need to account for how and why this outage occurred." She conceded the episode would strain public patience: "Australians expect a baseline of services when it comes to their telcos. There's a reason telcos are the least trusted industries in Australia — it's because of days like today."

Opposition communications spokesperson Sarah Henderson branded the government's response "totally inadequate". "Australians are still waiting for the outcome of ACMA's inquiry into the Optus triple-zero outage last September but all we have heard is silence," she said, urging the watchdog to deliver its report within seven days.

Opposition leader Angus Taylor and One Nation MP Barnaby Joyce called for an investigation into whether the outage was connected to China's ballistic missile testing on Monday. "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. Joyce told Sky News he didn't want to be a "conspiracy theorist" but suspected Chinese involvement: "I hope that that's investigated and cleared as not part of the process." Prime Minister Anthony Albanese dismissed the idea, saying Telstra had seen no sign of foul play: "What Telstra have indicated to the government is that they don't see this as being, there's no evidence of it being malicious, but those investigations are underway."

RMIT University associate professor Mark Gregory told SBS News the regulator is failing to hold telcos to account. When Vodafone suffered a major outage in June, its service page could not update customers properly, he said — "Vodafone were non-compliant. Have they been fined by the ACMA? No. Now, the same thing's happened with Telstra. What is the ACMA going to do about it? Well, nothing, because the ACMA is the telcos' mate. They're not acting as a regulator, they're acting as best buddies with these companies."

New reforms took effect in June requiring telcos to measure and report signal strength so customers can compare providers; Telstra responded by shrinking its claimed mobile coverage area by almost a third. Gregory argued the laws fall short because they don't compel the ACMA to publish a report after every significant outage — a gap he called a "total failure". The reforms followed a string of high-profile incidents, most notably Telstra's major 2024 system failure that disrupted emergency lines. That fault was fixed in an hour and a half, but a Victorian man died after his family's emergency calls were delayed during his cardiac arrest, and the company was fined $3 million after a probe. Gregory advised Australians to keep cash on hand, maintain WiFi options and know which neighbours use other networks in case of emergency.

On the railways, dozens of V/Line services stopped dead on the tracks and sat idle at regional and suburban Melbourne stations, The Age reported, with only very limited replacement coaches available at short notice and passengers told to put off travel. Around 70,000 Victorians ride V/Line trains daily. Transport for NSW likewise told passengers to delay journeys, warning "significant delays are expected to all services", and the Australian Rail Track Corporation suspended operations across its 9,500km network, hitting major freight and passenger routes.

Angry customers vented on social media, with some saying their businesses had suffered and others demanding compensation. On DownDetector, 53 per cent of reports concerned mobile signal, 40 per cent mobile internet and 4 per cent voice calls. Complaints poured in from every state and territory, covering both regional and metropolitan areas, with reports spiking at 6.30am before tapering off.