The Australian Communications and Media Authority has commenced Federal Court proceedings against Optus Mobile Pty Limited, alleging the telecommunications provider breached its legal obligations during the September 2025 network outage that prevented hundreds of Australians from accessing the Triple Zero emergency call service.
The legal action relates to the 18 September 2025 outage, when a network firewall upgrade disrupted emergency calling capabilities for Optus customers across South Australia, Western Australia, the Northern Territory and parts of far-west New South Wales. The outage lasted approximately 13 hours before the fault was identified and rectified.
According to the ACMA, Optus allegedly breached two fundamental obligations under Australia’s emergency call regulations on 1,005 occasions. The regulator claims Optus failed to provide end users with access to the emergency call service and failed to ensure emergency calls were carried to the appropriate emergency service termination point.
ACMA Chair Nerida O’Loughlin said the ability to contact Triple Zero is one of the most critical responsibilities of any telecommunications provider.
“Australians rightly expect that when they call Triple Zero, their call will connect,” O’Loughlin said.
“The circumstances of this outage meant that did not reliably occur, leaving people unable to connect to potentially lifesaving services.”
She added that providing access to the emergency call service “is not optional” and represents “the most important public safety responsibility telecommunications providers have.”
Independent investigations into the incident found that approximately 605 attempts were made to contact Triple Zero during the outage, with around three-quarters of those calls failing to connect. The outage was ultimately traced to a routine firewall upgrade that incorrectly blocked emergency calls while allowing standard voice services to continue operating.
The incident prompted widespread scrutiny after investigators linked two deaths to unsuccessful attempts to reach emergency services during the outage. It also raised questions about Optus’ monitoring and escalation processes, with subsequent reviews finding the company received customer reports of emergency call failures hours before the issue was fully investigated.
As the matter is now before the Federal Court, the ACMA said it would make no further public comment on the proceedings.
In a statement reported following the commencement of proceedings, Optus acknowledged the court action but said it would not comment further while the matter is before the courts.
The company said its focus remains on strengthening network resilience and improving customer outcomes through investments in infrastructure, enhanced operational processes and implementation of the recommendations arising from the independent review led by Dr Kerry Schott.
The proceedings represent another significant regulatory challenge for Australia’s second-largest telecommunications provider, following earlier enforcement action related to the nationwide Optus outage in 2023, which resulted in penalties exceeding $12 million.
If the Federal Court finds the allegations proven, the matter could result in substantial financial penalties, with each alleged contravention carrying significant maximum penalties under Australian telecommunications legislation.
