Summary

  • The ACMA's investigation into the 8 November 2023 Optus outage apportioned 2,145 unsuccessful emergency calls across named legal entities: 2,091 on Optus Mobile emergency telephone services, 42 via Optus Networks and 12 via Optus Internet; 2,144 were calls to 000 or 112 and one to 106 (ACMA investigation report).
  • Section 148(1) contraventions of the TCPSS Act were counted per entity: Optus Mobile 4,560; Optus Networks 113; Optus Internet 24; Optus Fixed Infrastructure 1 (ACMA investigation report).
  • Welfare-check accounting: 183 checks were conducted of 2,145 calls; exemptions under paragraphs 28(2)(b) and 28(2)(c) covered 31 and 1,562 calls respectively, leaving 369 required checks that were not made — 361 attributed to Optus Mobile and 8 to Optus Networks (ACMA investigation report).
  • Three subsidiaries paid infringement notices totalling $12,000,420 in the October–December 2024 quarter (ACMA penalty notice; ACMA quarterly report).
  • On 30 July 2026 the ACMA commenced Federal Court proceedings against Optus Mobile Pty Limited alone over the 18 September 2025 outage, alleging 1,005 contraventions with a statutory maximum of $250,000 each — allegations, not findings (ACMA; Singtel/Optus SGX announcement).

A ledger, not a headline

The most useful thing in the ACMA's file on the November 2023 outage is not the number 2,145. It is the structure underneath it. The investigation, opened on 13 November 2023 under section 510 of the Telecommunications Act 1997 (ACMA investigation report), did not treat "Optus" as one accountable thing. It counted failures against four named legal persons: Optus Mobile Pty Limited (ACN 054 365 696), Optus Networks Pty Limited (ACN 008 570 330), Optus Internet Pty Limited (ACN 083 164 532) and Optus Fixed Infrastructure Pty Limited (ACN 092 450 783).

Attachment B of the report lists the 2,145 unsuccessful emergency calls by the service the caller was on: 2,091 by end-users on an Optus Mobile emergency telephone service, 42 via Optus Networks and 12 via Optus Internet. Of those, 2,144 were calls to 000 or 112; one call to 106, the text-based emergency service for people who are Deaf or have a speech or hearing impairment, came from an Optus Networks service. Twenty-eight test calls made by Optus employees were excluded because they were not emergency calls — an exclusion that keeps the count a measure of public harm rather than internal noise (ACMA investigation report).

The statutory accounting splits further. For section 15 of the Emergency Call Service Determination — the duty to give end-users access to the emergency call service — the ACMA found Optus Mobile contravened on 2,091 occasions, Optus Networks on 41 and Optus Internet on 12. For subsection 19(1) — the duty to carry calls to the relevant termination point — the counts are 2,091, 42 and 12 respectively. And for section 148(1) of the TCPSS Act, the counts run much higher: 4,560 for Optus Mobile, 113 for Optus Networks, 24 for Optus Internet, and one for Optus Fixed Infrastructure (ACMA investigation report).

Why does the same outage produce both twelve and twenty-four for Optus Internet? Because the duties are different. The twelve is a count of failed emergency calls attributable to that entity's services; the twenty-four is a count of contraventions of a separate statutory provision, each counted on its own legal hook. A reader who collapses them into one number loses exactly what the report is built to preserve: which duty, owed by which company, failed how many times.

The humane core: welfare checks that were not made

Behind the call counts sits a second ledger, and it is the one that concerns people rather than connections. Under subsection 28(1) of the Determination, carriers must attempt welfare checks on people who tried and failed to reach the emergency service. The ACMA's accounting of the 2,145 calls runs: 183 welfare checks were conducted; the paragraph 28(2)(b) exception applied to 31 calls and the paragraph 28(2)(c) exception to 1,562 — 1,593 exempt in total — leaving 369 calls on which a welfare check was required and not made. The contraventions attach to entities: 361 to Optus Mobile, 8 to Optus Networks (ACMA investigation report). ACMA's public summary states plainly that Optus "failed to conduct 369 welfare checks on people who had tried to make an emergency call" (ACMA).

The exemptions are load-bearing. If the 28(2)(b) and 28(2)(c) carve-outs had been narrower, the 369 figure — and the contravention counts built on it — would be materially larger. Showing the exemptions alongside the total is not accountant's pedantry; it is what makes the number an accurate measure of care owed and not delivered, rather than an inflated one.

What the penalties settled — and what they did not

In November 2024 the ACMA issued separate infringement notices to Optus Internet, Optus Mobile and Optus Networks, each a subsidiary of Singtel Optus Pty Limited (ACMA publications page). The subsidiaries paid them. ACMA's quarterly enforcement report records three infringement notices totalling $12,000,420 paid in the October–December 2024 quarter (ACMA quarterly report); its media release rounds the figure to "more than $12 million" and adds the Chair's assessment that the outage "should have been preventable" (ACMA; corroborated by ABC News and The Guardian).

An infringement notice is an administrative settlement: it closes a matter inside the regulator's discretion without any court testing the findings. That is a legitimate and common enforcement tool, but it has a known property — the price of failure becomes a known cost. The test of whether the payment functioned as a corrective lever or a priced risk is what happened next.

What happened next is a second outage. On 18 September 2025, Optus services again failed in a way that touched Triple Zero access. ABC News reports that outage lasted almost 14 hours and was linked to two deaths; it also reports that the Optus-commissioned review by Kerry Schott found the call centre did not escalate warnings from five callers who said Triple Zero calls were failing, and identified up to ten crucial mistakes by Optus and its contractor Nokia (ABC News). These are reports and a commissioned review's claims — the review was paid for by the subject, and the death linkage is reported, not adjudicated. They belong in the record with those labels attached.

The court rung

On 30 July 2026 the ACMA commenced proceedings in the Federal Court against Optus Mobile Pty Limited over the September 2025 outage. The regulator alleges Optus Mobile breached two legal obligations — sections 15 and 19 of the Telecommunications (Emergency Call Service) Determination 2019 — on 1,005 occasions, and seeks declarations and pecuniary penalties, with a statutory maximum of $250,000 per contravention (ACMA). The Communications Minister, Anika Wells, welcomed the action (Ministerial statement).

Optus's own market announcement, filed by Optus Finance Pty Limited, confirms the filing, states that the company is reviewing the pleadings and will respond in due course, and notes that it cannot determine the quantum of any potential penalties. The same announcement records the corporate structure: Optus Finance Pty Limited and Optus Mobile Pty Limited are wholly-owned subsidiaries of Singtel Optus Pty Limited (SGX announcement).

Every verb in that paragraph matters. The 2023 findings were determined and settled; the 2025 matters are alleged. No court has made findings on the 1,005 counts, and the $250,000-per-contravention figure is a statutory ceiling, not an expected penalty. Treating the pleading as proof would be precisely the error this article exists to avoid.

What this adds beyond the prior coverage

BTW published a briefing on this entity one day before this report: "Twelve calls inside a twelve-hour outage: Optus Internet Pty Ltd and the emergency-call record" (2026-09-25), which traces the apportionment of the 12 of 2,145 failed calls and the operator's first public count of 228, and asks whether the repair held. The checkable delta of the present report beyond that baseline is threefold. First, the per-entity statutory accounting in full — including Optus Internet's 24 s148(1) contraventions and the s15/s19(1) split (2,091/41/12 and 2,091/42/12) — not only the call-count attribution. Second, the welfare-check arithmetic with its exemptions shown (183 conducted, 1,593 exempt, 369 required), which the prior briefing referenced but did not unpack. Third, the enforcement escalation itself: the named adjacent coverage is the November 2024 infringement-notice cluster (ACMA, [https://www.acma.gov.au/articles/2024-11/optus-pays-12-million-penalty-triple-zero-outage]) and the 30 July 2026 Federal Court proceeding, which names Optus Mobile Pty Limited and not Optus Internet — a narrowing with consequences for where accountability is now being tested.