Telstra customers are still having trouble calling triple zero on Thursday morning as the telecommunications giant confirmed a secondary issue stemming from Wednesday’s national outage continued to affect services.

Some who tried to call the emergency hotline were receiving an error message before their phones would try to connect to an alternative network, Telstra said.

The company urged customers to immediately redial triple zero if their first call didn’t connect, as there had been “good success” of getting through on a second attempt.

The telco earlier recommended callers wait for their phone to connect to another network, or use a different device to make their call.

In a statement early Thursday, Telstra said: “We’re deeply sorry for the impact this issue has had on so many people.”

As of 6.30am on Thursday morning, Telstra said the occurrence of the secondary triple-zero issue had been reduced by 90%.

But the minister for industry, Tim Ayres, told the ABC on Thursday “100% is the only acceptable figure here”.

The telco’s issues have continued to wreak havoc across Australia.

All the trains on Victoria’s regional rail network were still suspended on Thursday morning, up to and including the morning peak travel period.

Telstra’s 4G network has been interfering with the back-up satellite phones used in the trains when the mobile network is unavailable, according to V/Line’s chief executive, William Tieppo.

In a statement, V/Line later said services would “gradually return from midday” Thursday.

“Delays and cancellations may continue across the day as we work to recover the full timetable,” it said.

Regional trains in New South Wales were also interrupted Thursday morning, though services have resumed on the Southern Highlands and Hunter lines.

The communications minister, Anika Wells, said she had not yet heard of any “adverse outcomes” linked to the continuing triple-zero issues as Ayres said there would be a full investigation.

“Communications and digital infrastructure [are] part of the lifeblood of the economy,” he said.

“We’ve got a transparent investigative framework and to apply penalties where it’s necessary.”

Thousands of customers were unable to make calls or access data on Wednesday after a software defect affected Telstra’s systems, the telco said.

The company made more than 300 welfare checks to people who attempted to dial triple zero during the episode.

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.

The Telstra chief executive, Michael Ackland, said on Wednesday the number of calls appeared to be higher than normal.

This suggested some may have been dialling triple zero to check if it worked during the outage, which customers have been urged not to do.

The opposition communications spokesperson, Sarah Henderson, defended her decision to call the emergency line during the outage.

“I accept the criticism, but what I will say is that I am in a unique position holding this government to account,” she told 2GB radio on Thursday.

“Telstra’s network is critical infrastructure, this should simply not be happening.”

Businesses also reported being unable to take customer payments due to interruptions to Eftpos terminals.

The Australian Communications Consumer Action Network’s chief executive, Carol Bennett, told Sky News the outage had caused huge disruptions in people’s lives.

“There certainly needs to be some kind of recourse to compensate customers and businesses who’ve lost a lot when it comes to these outages,” she said.

The telco blamed Wednesday’s issues on a software fault that caused the “GPS node” to reset.

This server tells the rest of the organisation’s systems what the most accurate time is to the nanosecond. A software reset changed the time and synchronisation, which was then passed on to the rest of the Telstra network.

Two deaths were linked to an outage at Optus in September 2025, which lasted almost 14 hours and affected hundreds of calls in four states and territories.

In June, Vodafone customers were left with intermittent reception and data issues across Australia.

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.