Optus has been hit with more than $12 million in penalties after thousands of customers were unable to call triple zero during last year's unprecedented network outage.

More than 2100 Optus customers were unable to call triple zero during a massive network outage in November 2023, where millions also lost phone and internet connections.

An investigation by the Australian Communications and Media Authority (ACMA) found the telco also failed to conduct more than 300 welfare checks on those who had tried to make an emergency call during the outage.

ACMA chair Nerida O'Loughlin said the size of the penalty was reflective of the breaches as triple-o was the most fundamental service telcos must provide to the public.

"When an emergency call fails to connect there can be devastating consequences for public health and safety," she said.

"Our findings indicate that Optus failed in the management of its network in a number of areas and that the outage should have been preventable.

"Optus also failed to follow up on the safety and wellbeing of more than 360 of its customers once the outage was resolved."

A Senate committee found Optus failed to provide honest and credible communication during last year's major outage and provided a range of recommendations. 

The committee called for a mandatory communications that obliges telcos to communicate to government, emergency services and the public during national outages. 

'Still hurts' 

Gold Coast pensioner Adrian Ashenden, 79, was one of the people impacted by the outage and was unable to call for emergency services. 

Mr Ashenden, who was undergoing treatment for cancer, said the incident still brings up painful memories one year later.

"I thought I might well be dying," he said. 

"It's not just about the lack of service at the time but the entirely uncaring attitude afterwards." 

 Mr Ashenden said he has contacted his mobile provider Catch Connect, which is powered by Optus, but has not received a reply.

"That really hurts, it really does … it was a serious incident and could have been fatal for me," he said. 

"[I am] hurt and angry that some company could be careless and not respond to the contact knowing the situation." 

Developing new industry standard

The ACMA said it was developing a new industry standard that would require a minimum level of customer communications from telcos during outages. 

"Beyond the penalties announced today by the ACMA, the Optus outage has directly led to changes for industry regulatory obligations in relation to emergency call services," Ms O'Loughlin said.

"This will require further actions and investment by telcos, including Optus, to provide better safeguards for consumers and enhance the triple-0 ecosystem so that Australians can have even greater confidence they will be able to get through to emergency services when they need it."

The ACMA added the government had agreed to a set of regulatory actions that aim to improve the performance of the entire telecommunications sector during network outages. 

This includes greater oversight of the triple-0 system and ensuring emergency calls could be consistently carried by other carriers when needed.

An Optus spokesperson said the company remained committed to continuously improving support for customers at critical times.

"We know we let our customers down — particularly those who should have received a welfare check from Optus," it said in a statement.

"Our entire team is committed to addressing all lessons from the outage." 

The telco added it had made important changes to better manage emergency calls and had also been talking to customers affected by the outage.