Optus has been accused of enabling scammers to prey on its customers in the latest damaging blow for the embattled telco.

Months on from a devastating triple-zero network failure that has been linked to multiple deaths, the telco has paid a six-figure fine for breaching anti-scam rules.

The Australian Communications and Media Authority found Optus’ Coles Mobile brand breached the rules 44 times in 2024, after scammers picked their way through its “vulnerable” third-party identity verification system.

At least four consumers had their mobile services taken over by scammers after they were able to skip parts of the verification process.

It meant the scammers could access the customers’ bank accounts, with ACMA finding reported losses of $39,000.

Optus was fined $826,320 – the maximum penalty the code allowed, ACMA’s Samantha Yorke said.

“While this was a one-off issue, which was quickly remediated, it is inexcusable for any telco not to have robust customer ID verification systems in place, let alone Australia’s second largest provider,” she said on Wednesday.

“Scammers are always looking for any weaknesses in systems, and on this occasion Optus left a vulnerability which directly exposed people to harm.”

Optus apologised and accepted the fine, blaming a technical issue within its porting system, which it said was managed by its service provider.

The technical issue was solved within 24 hours and the service provider had since strengthened its resilience, it said.

“Optus continues to work closely with government, the banking sector, and industry partners to make it increasingly difficult for criminals to misuse telecommunications services for identity theft,” a company spokesperson said.

It is a fresh blow for the telco’s badly-damaged image after a major outage in which more than 600 triple-zero calls could not be connected.

But Optus has defended a near-18-hour delay in providing government authorities with key details, including that deaths had been linked to the outage.

A fresh problem was reported in early November, with a fibre break in the Hunter Valley region of NSW affecting customers’ ability to contact emergency services.

Optus has commissioned an independent review into the outages, led by Kerry Schott. It is due to report within weeks.

It also pledged to hire 300 new Australia-based contact centre workers and brought forward plans to “on-shore” network operations in Australia.

-AAP