ACMA sues Optus over Triple Zero outage that left callers stranded
Optus is facing millions of dollars in fines after Australia’s media watchdog dragged the telco to the Federal Court today over a major network failure that blocked Triple Zero calls in 2025.
The Australian Communications and Media Authority (ACMA) launched legal proceedings against Optus Mobile on Thursday, alleging the company breached its fundamental legal obligations 1,005 times when a 13-hour network disruption on September 18, 2025, left customers unable to reach emergency services.
A screenshot of a mobile phone during the 2023 Optus outage. Nine
The outage - triggered by a firewall upgrade - impacted users across South Australia, Western Australia, the Northern Territory, and parts of New South Wales, with over 600 emergency calls failing to connect.
The incident was later linked to two deaths.
What ACMA is alleging
The regulator claims Optus Mobile breached two distinct legal duties by failing to provide customers access to an emergency call service and ensuring that those emergency calls were carried to the correct termination point.
With maximum penalties reaching $250,000 per breach, the telco faces staggering financial penalties if found liable by the court.
ACMA Chair Nerida O’Loughlin said emergency access was non-negotiable for Australia’s telcos.
“Australians rightly expect that when they call Triple Zero, their call will connect. The circumstances of this outage meant that did not reliably occur, leaving people unable to connect to potentially life-saving services,” O’Loughlin said.
“Giving access to the emergency call service is not optional, it is a fundamental legal obligation and the most important public safety responsibility telecommunications providers have.”
A spokesperson for Optus said, as the matter was now before the Court, it would be inappropriate for the telco to comment on the legal proceedings.
“Our focus remains on building a stronger and better Optus,” the spokesperson said.
“We continue to invest in network resilience, strengthen our systems and processes, build and foster a culture of transparency and accountability, and improve the services our customers and communities rely on every day.”
An independent review into the September 2025 blackout, led by former Treasury head Dr Kerry Schott and released in December 2025, revealed widespread issues and an overall “lack of care” about mistakes that led to the incident.
The report slammed Optus over systemic failures, critical delays in identifying the issue, and severe communication breakdowns. It revealed offshore customer service staff repeatedly dismissed caller warnings about failing Triple Zero connections because they were completely unaware a major network failure was underway.
Optus accepted the review’s findings in full and vowed to overhaul its network management and emergency escalation procedures.
Optus chairman John Arthur said the report was a “sobering read”.
“We are deeply sorry for the 18 September outage that impacted Triple Zero services and the consequences for any Australians who were trying to reach emergency services,” he said.
“We recognise the scale of the challenge and will act decisively to make the necessary changes to strengthen the business and rebuild trust.”
History repeats for telco giant
The legal onslaught comes after Singtel Optus subsidiaries paid more than $12 million in penalties following a similar nationwide blackout in November 2023, which also cut off Triple Zero access.
O’Loughlin said the rapid recurrence of another major failure was a key driver behind taking the company to court.
“The recurrence of a major network outage affecting emergency calls so soon after the November 2023 outage is a significant concern and one of the reasons the ACMA has decided to take this matter to court,” she said.
The ACMA is seeking formal court declarations against Optus Mobile along with substantial pecuniary penalties paid to the Commonwealth.
Because the matter is now active before the Federal Court, the regulator stated it would make no further public comment.
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