Australia’s communications regulator has sued Optus over last year’s Triple Zero outage, alleging the telco failed to connect emergency calls on 1005 occasions and exposing it to penalties of more than $250 million.

The Australian Communications and Media Authority on Thursday filed civil penalty proceedings in the Federal Court against Optus Mobile over the September 18 outage, when a bungled firewall upgrade blocked calls to Triple Zero across South Australia, Western Australia, the Northern Territory and Far West NSW for about 13 hours. The outage was linked to two deaths.

The regulator alleges Optus Mobile broke the law twice over for each failed call: once by not giving callers access to the emergency call service, and again by not carrying those calls to the relevant termination point. The maximum penalty is $250,000 per contravention.

ACMA chair Nerida O’Loughlin said the obligation was fundamental. “Australians rightly expect that when they call Triple Zero, their call will connect,” she said on Thursday. “Giving access to the emergency call service is not optional.”

Optus Mobile and other Singtel subsidiaries paid more than $12 million over similar failures in November 2023. O’Loughlin said the repeat so soon afterwards was a significant concern and a reason for going to court.

An independent review by business veteran Kerry Schott made 21 recommendations and called the failures inexcusable, finding a 40-page crisis management document was too dense for staff to follow. Optus boss Stephen Rue, who kept his job, told a Senate inquiry Optus had a culture of carelessness, and has since moved call centre roles onshore, tightened escalation and replaced executives across network security, technology and risk.

Communications Minister Anika Wells welcomed the action by the independent regulator and said the alleged failures were serious.

“Australians rightly expect to reach Triple Zero when they need it most, and telcos are legally obligated to ensure that connection occurs,” Wells said. She declined to comment further while the matter is before the court.

An Optus spokesman said the company acknowledged the proceedings, but it would be inappropriate to comment on them.

“Our focus remains on building a stronger and better Optus,” the spokesman said, pointing to continued investment in network resilience and a culture of transparency and accountability. Optus said the work was being supported by its transformation program and its implementation of the recommendations from the Schott review.

The proceedings land three weeks after Telstra’s nationwide outage on July 8, which affected more than 600 Triple Zero calls and left millions of customers without mobile services.

No deaths have been linked to that failure, which the ACMA is separately investigating and which prompted the regulator to seek stronger powers to compel telcos to prove they have complied with the law.

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