Telstra Points To Data Centre Time Sync Fault After Nationwide Network Outage

Triple Zero calls, regional trains and payment terminals were disrupted as the regulator opens an investigation.

Telstra says close to 90 per cent of calls and data are flowing again across its mobile network after a nationwide outage cut voice and data services for customers around the country, halting regional trains, knocking out eftpos terminals and preventing some Triple Zero calls from connecting.

The disruption began in the early hours of the morning, with outage tracker Downdetector recording a spike in reports from about 5am AEST. Reports peaked in the thousands shortly after 6am before falling to under 500 by early afternoon as services returned.

“We’ve made good progress restoring services, with just under 90 per cent of calls and data now flowing successfully across the network,” a Telstra spokesperson stated. “Our teams are working as quickly as possible to restore remaining services and get all customers back online.”

Communications Minister Anika Wells confirmed the network had “largely returned to business-as-usual” just before 2pm AEST, with only a small number of devices still experiencing issues.

Customers of providers that resell Telstra’s network, including Boost, Aldi Mobile, Tangerine, Belong and Everyday Mobile, also lost service, while Optus reported its own systems were operating as normal.

Everyday Mobile from Woolworths put the potential impact on its service at more than 100,000 carriage services, warning that two-factor authentication SMS codes, recharges, activations and its My Account portal would take longer to recover than core connectivity.

Telstra, which provided about 24.9 million retail mobile services as of June last year, is publishing ongoing updates and customers can check outages by address or suburb at telstra.com.au/outages.

Time synchronisation fault suspected

Chief Financial Officer Michael Ackland, acting as delegate for Chief Executive Vicki Brady while she is on leave overseas, told reporters there was no evidence of malicious activity but the root cause was not yet known.

He pointed to servers in Telstra data centres in Sydney and Melbourne, where a time synchronisation function had stopped working correctly.

“You can imagine that lots of computer systems have to synchronise time,” Ackland explained. “It’s one of the ways that you authenticate what’s going on in the network. And the time synchronisation in those nodes wasn’t working as it should. We don’t know why yet.”

Nodes keep consistent time across the Telstra network, meaning a fault in one location can ripple through the rest of the mobile network.

“As we have restored those nodes, they will then update through the servers, and it could take some time before we’re not seeing any intermittent responses,” he added. “But it should become less as we restore the nodes.”

Ackland would not commit to a full restoration timeframe and apologised for the disruption.

“Our investment in resilience and cybersecurity and redundancy in our network is significant, but it is a big and complex network, and from time to time, issues do occur,” he told the briefing.

Telstra advised customers still having problems to restart their phones “rather than just switching on airplane mode”.

Shares in the telco fell 2.8 per cent to about $5 in early trade, and Ackland confirmed the stock would not be placed in a trading halt. Brady has been briefed throughout and will return “in the coming days”, a spokesperson added.

Some Triple Zero calls failed

While Telstra maintains emergency calls follow different settings in its network and were “not impacted in the same way”, both the company and the federal government confirmed some callers could not get through to Triple Zero.

“The core Triple Zero system remains operational, with connected calls flowing as expected from carrier networks to the emergency call person and on to state and territory emergency services dispatchers,” Wells stated. “However, the Triple Zero custodian has advised that some callers were unable to connect to the ECP, and that these are being now investigated by Telstra and welfare checks are in progress, as is required by the law.”

Wells said camp-on arrangements introduced after an earlier Optus emergency call outage, which shift failed Triple Zero calls onto other carriers, had worked across the TPG, Optus and Vodafone networks.

About three dozen welfare checks were under way as of mid-morning, according to figures Telstra provided to the government, though some may relate to callers who got through on a second attempt.

Police in Western Australia and South Australia warned the outage was stopping some Triple Zero calls from Telstra services and urged people to check on vulnerable family members, friends, neighbours and co-workers.

“Triple Zero systems are not affected, but you may not be able to reach Triple Zero if you are calling from a Telstra device,” a NSW Police spokesperson advised. “If you try to call Triple Zero and can’t get through, we recommend using another device, a landline or wi-fi calling.”

WA Police attended a commercial premises in Bull Creek after a failed emergency call, confirming it was made in error and that no assistance was required.

Ackland asked customers “not to test and try out Triple Zero unless you need Triple Zero”, a message echoed by ministers.

Emergency Management Minister Kristy McBain described it as “absolutely outrageous” that Shadow Communications Minister Sarah Henderson had been making test calls to the number while welfare checks were still being run.

Trains brought to a stand

The outage flowed through to transport operators that depend on Telstra for critical communications.

V/Line suspended all regional Victorian services after its train radio system dropped out with about 100 trains on the network.

“That train radio system actually locates the train and talks back to our control room. If we don’t see where that train is, we stop the train immediately because that’s a safety measure that we put in place as part of our safety procedures,” V/Line Chief Executive Will Tieppo explained.

The operator regained visibility of all 178 of its trains by about 11.30am but kept services parked until the radio network stabilised.

“We are still seeing instability in that network and until we get a really stable network, we’re not willing to take the risk and run trains until that network is fully stable,” Tieppo added, saying he hoped to restore services for the afternoon peak but could not promise it.

In NSW, trains stopped on the Hunter Line between Newcastle Interchange and Maitland and on the Southern Highlands Line between Campbelltown and Moss Vale, with replacement buses initially unavailable.

Transport for NSW Acting Coordinator-General Matt Longland said services between Sydney and Canberra were shut down, with at least one train stopped outside Sydney after it lost communications with a control centre.

The Australian Rail Track Corporation brought services across its 9,500-kilometre national network to a stand under emergency protocols after field teams lost the ability to make or receive emergency calls, affecting interstate services including The Ghan, Indian Pacific and NSW TrainLink’s XPT.

“As a safety precaution, ARTC has implemented established emergency protocols and safely brought rail services on the network to a stand while the telecommunications outage is resolved,” a spokesperson said.

McBain, who is also Acting Infrastructure and Transport Minister, confirmed freight operations were paused and asked the National Emergency Management Agency to convene a National Coordination Mechanism meeting with relevant Australian government agencies, state and territory agencies and Telstra.

Canberra’s transport authorities investigated a likely link between the outage and faults in the ACT’s MyWay+ ticketing system, while hundreds of traffic lights in South Australia fell back to basic programming rather than responding to traffic conditions.

Deakin University took lifts out of operation across its campuses because their emergency intercoms run on the Telstra network, offering staff escorts to any of its roughly 60,000 students requiring accessibility assistance.

Payments and platforms knocked offline

Eftpos terminals that connect over 4G failed at businesses around the country, pushing some cafes to cash-only trade.

Tyro, which services terminals for about 80,000 businesses, confirmed some customers could not process transactions and advised merchants to connect via ethernet or wi-fi until service was restored.

The Commonwealth Bank reported similar problems with its merchant terminals, telling customers they could switch to the Optus network or use wi-fi where available.

Uber said the outage was affecting some merchants, delivery people and driver partners on the Telstra network, while EV charging operator Chargefox reported a small number of its public chargers offline.

Stranded commuters took to Reddit to report being stuck on stationary V/Line trains, while taxi passengers described being unable to complete payments.

‘Least trusted industry’

Prime Minister Anthony Albanese described the outage as “deeply concerning” and disruptive to people’s lives, adding: “None of it is, of course, acceptable.”

The Australian Communications and Media Authority is opening an investigation into whether Telstra complied with its regulatory obligations, and Wells confirmed the Triple Zero custodian was keeping a detailed account of who knew what and when.

“I’d say that telcos are the least trusted industry in our country as we stand today and days like today demonstrate exactly why Australians feel that way,” Wells told reporters. “It would be up to Telstra to make things right with their customers today.”

Asked whether fines would follow, she declined to pre-empt the process: “I can tell you that both of those people are in a preliminary investigation stage and that everything we are doing is being tracked in order to get to the bottom of it, and that justice is served.”

Telstra was fined more than $3 million in 2024 over an earlier outage that prevented customers reaching Triple Zero, with the regulator finding 473 breaches of emergency call rules after incorrect numbers on a backup phone list stopped 127 calls from connecting.

Opposition Leader Angus Taylor argued Wells should have cut short her leave and, along with One Nation MP Barnaby Joyce, called for investigators to rule out Chinese involvement, pointing to a People’s Liberation Army missile test earlier in the week.

“I don’t know whether there’s any connection, I have no idea. But it’s no wonder Australians are starting to ask questions like that,” Taylor said.

Wells rejected the suggestion. “As a general principle, I think when it comes to matters of national security, you shouldn’t make stuff up. You’ve heard from Telstra’s acting CEO there’s currently no evidence to suggest that those things are the case. So I think it’s irresponsible.”

Union links failure to job cuts

The Communication Workers Union tied the outage to Telstra’s workforce reductions, after the telco moved in February to cut or outsource 650 roles to Infosys, eight months after axing 550 other positions.

“Triple Zero calls had to be diverted. Small business owners were unable to use eftpos terminals for trade. Australia Post workers were unable to use their scanners to deliver parcels. Regional trains had to suspend services. This is all because of a massive failure of Telstra’s network,” CWU National Secretary Shane Murphy stated.

“This is what happens when you prioritise the bottom line over critical services; you get an unreliable network that lets Australians down time and time again.”

Murphy urged Telstra to invest in its domestic workforce and cut back on outsourced services.

The Australian Communications Consumer Action Network argued the incident underlined the absence of enforceable reliability standards for telcos.

“Every telco outage carries a cost: to public safety, to business operations, to social connection and to the economy at large,” ACCAN Chief Executive Carol Bennett warned. “Consumers are right to ask: how much longer before these companies are held to account for their networks, with enforceable reliability requirements rather than voluntary commitments?”

Crisis communications under fire

Telstra’s public handling drew criticism of its own, with the telco’s initial acknowledgement, a brief social media post referring to an issue affecting “some mobile calls and data connections” and suggesting customers retry, standing as its main update for more than two hours.

Media industry publication Mumbrella argued the early messaging underplayed the incident and fell short of the scale of the problem, with Editorial Director Hal Crawford writing that “this is as bad as it gets for Telstra’s reputation”.

Many customers initially assumed the fault lay with their own devices, only discovering later that the whole network was down, he wrote.

Telstra committed to further updates until all services are back online.

Last Updated on July 8, 2026 by Nick Ross