ACMA takes Optus Mobile to court over 2025 Triple Zero outage

The Australian Communications and Media Authority (ACMA) has today commenced proceedings in the Federal Court against Optus Mobile Pty Limited (Optus Mobile) in relation to  outage on 18 September 2025, which affected some people’s ability to connect to the emergency call service.

The ACMA alleges that during the outage, Optus Mobile breached two separate legal obligations on 1,005 occasions in that it failed to give end-users who made emergency calls using an emergency telephone service supplied by Optus Mobile access to the emergency call service, and ensure that those emergency calls were carried to the relevant termination point.

ACMA Chair Nerida O’Loughlin said that the provision of access to the emergency call service is essential to protecting the Australian public.

“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," she 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."

The proceedings follow earlier enforcement action taken by the ACMA arising from the Optus November 2023 outage.

Singtel Optus subsidiaries, including Optus Mobile, paid more than $12 million in infringement notice penalties imposed by the ACMA for breaches relating to emergency calls. These included failures to give access to the emergency call service during that outage.

“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," said O'Loughlin.

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

From the court, the ACMA is seeking declarations that Optus Mobile contravened the Telecommunications (Consumer Protection and Service Standards) Act 1999 on 1,005 occasions by failing to comply with obligations under sections 15 and 19 of the Telecommunications (Emergency Call Service) Determination 2019.

It's also seeking an order that Optus Mobile pay pecuniary penalties to the Commonwealth for these contraventions.

The maximum penalty available to the court is $250,000 per contravention. 

The Hon Anika Wells MP, the government's Minister for Communications and Minister for Sport, released her own short statement, saying she welcomes the action being taken by ACMA.

Last year, the Australian Information Commissioner filed civil penalty proceedings in the Federal Court against Optus following the company's 2022 data breach.

Earlier this month, Telstra CEO Vicki Brady told a Senate ⁠inquiry that an outage a week earlier was likely caused by an undocumented design change and a missed software update on a network ‌time-keeping device.

Maintenance work on a network timing and synchronisation equipment triggered a software configuration that reset the device's date to 2006, which resulted in authentication certificates failing across Telstra's network, disrupting voice and data services including ​calls to Triple Zero.