The Australian Communications and Media Authority has launched Federal Court action against Optus Mobile over the September 2025 network outage that left some customers unable to make emergency calls.

The outage struck early in the morning and caused widespread disruption to mobile voice and data services across parts of the Optus network.

Customers reported calls dropping out mid‑dial and emergency calls failing to connect, with triple-0 operators confirming some calls simply did not reach the network.

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Emergency services warned at the time that any interruption to triple-0 access poses a serious public safety risk.

During welfare checks following the incident, two deaths of individuals who had attempted or likely attempted to contact emergency services were flagged — a 68-year-old woman in Queenstown, South Australia, and a man from Western Australia.

The Optus outage has been linked to two deaths possibly as a result of emergency calls failing to connect. Credit: AAP

ACMA alleges Optus Mobile breached two separate legal obligations 1005 times, claiming the telco failed to provide access to the emergency call service and did not ensure those calls were carried to the correct termination point.

ACMA chair Nerida O’Loughlin said the outage undermined a core public safety requirement.

“Australians rightly expect that when they call triple-0 their call will connect,” she said.

“The circumstances of this outage meant that did not reliably occur, leaving people unable to connect to potentially life‑saving services.

“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.”

The regulator’s investigation began immediately after the outage, focusing on whether Optus met its obligations under the Telecommunications (Emergency Call Service) Determination.

The incident came less than two years after the major November 2023 Optus blackout, which had already triggered heavy regulatory scrutiny and more than $12 million in penalties for emergency call failures.

O’Loughlin said the recurrence of another major outage so soon after the 2023 incident was a key factor in escalating the matter.

“The ACMA will not hesitate to take strong enforcement action where alleged telco failures have jeopardised public access to the critical emergency call service,” she said.

The regulator is seeking declarations that Optus Mobile contravened the Telecommunications (Consumer Protection and Service Standards) Act 1999 on 1005 occasions, along with court‑ordered financial penalties.

The maximum penalty if found guilty is $250,000 per contravention.

With the matter now before the court, ACMA says it will not provide further comment.

Optus said it “acknowledges the proceedings commenced today” but also said it was “inappropriate to comment on the legal proceedings”.

“Our focus remains on building a stronger and better Optus. 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,” the telco said.

“This work is being supported by our broader transformation program and implementation of the Dr Schott report recommendations.”