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 impact calls.

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

Customers have been urged to wait for the phone to connect to another network, or use a different device to make their call.

The federal communications minister, Anika Wells, told ABC radio: “In some instances calls are going straight to message bank. In some instances, 000 calls were not going through.

“It has been largely resolved, but there are still residual problems,” she said.

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 that “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.

Though services could resume before the afternoon peak, Tieppo did not commit to a time.

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

Wells said she had not yet heard of any “adverse outcomes” linked to the continuing triple-zero issues as Ayres revealed there would be a full investigation into the outages.

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

“The framework is there to manage those, to make sure 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.

Telstra’s 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 triple zero 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.”

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.

Telcos have come under increasing scrutiny in recent years following major issues at some of Australia’s biggest providers.

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.