Telstra testing has revealed some Samsung mobile phone users may be unable to call triple-0 in an emergency with more than 70 models found not to be connecting correctly. 

Telstra said the issue affected 11 older model Samsung Galaxy phones which users would need to replace with newer devices, and about 60 models that required system updates.

It said affected customers would be notified via email or SMS.

The telco said legal obligations meant customers who owned models that needed to be replaced would be blocked from its network if their phones were not replaced within 28 days of being notified.

“Under the government’s Emergency Service Call Determination, all mobile network operators are required to block devices from their networks that are not configured to access emergency call services,” Telstra posted online.

About 60 other Samsung models required an immediate software update to ensure they could reach triple-0 in an emergency.

Telstra performed the testing over the last nine days.

In a statement to the ABC it said, “Our engineers proactively completed testing in our lab after a report of an issue on another operators’ network.”

“Once we discovered the issue through our testing, we notified Samsung and the other mobile network operators.”

In a website post, Telstra said the testing showed that the phones were not connecting to the Vodafone network when trying to make triple-0 calls, but only when the Telstra or Optus networks were unavailable.

“For Telstra customers, the primary mobile network is Telstra and another available mobile network would be Optus or Vodafone in Australia,” it posted online.

“After completing some recent testing, we’ve identified a number of older Samsung mobile devices that are not correctly connecting to the Vodafone mobile network when other mobile networks are unavailable.”

Optus has also published a post on its website which said it had begun contacting affected customers and it would begin blocking phones that were not replaced as soon as 28 days after the customer was notified.

During a network outage a mobile phone is meant to use what is known as a “camp on” system to find the next available network but Telstra said this was not working.

Australian Communications Consumer Action Network (ACCAN) CEO, Carol Bennett, said the issue could potentially affect thousands of customers.

“We believe it’s in the tens of thousands [with Optus and Telstra]. We’re not sure how many TPG customers are directly affected by this issue,” she said.

Telstra said almost 20,000 devices that used its network would need to be replaced and the most recent phone was launched in 2017.

Some customers with vulnerable circumstances would be given a free replacement, however others would need to buy one.

The development adds to a crisis of confidence in the triple-0 emergency system following two recent Optus outages.

The largest outage in September has been linked to three deaths and hundreds of customers were unable to make emergency calls, breaching the telco’s legal obligations to ensure emergency calls were carried and prompting multiple ongoing investigations.

TPG denies network was to blame

Vodafone’s owner TPG Telecom said it had recently received “new advice from Samsung” about concerns with some devices and Telstra had informed it about its testing results.

It denied the Vodafone network was to blame for the failed calls.

“It is not a fault of the Vodafone network, but a limitation in how certain devices were originally configured to search for emergency connectivity,” it said.

“TPG Telecom continues to monitor the handsets used on its network and actively work with customers impacted by the emergency call service determination to ensure they can continue to access triple-0.”

The company said it would offer free or subsidised handsets to some customers and customers who did not act would have their phones blocked.

Samsung did not answer questions about why its devices were unable to make emergency calls and who was at fault.

In a statement the company said, “Samsung and its carrier partners are working together to ensure all devices operate reliably in every emergency situation.”

Optus said in a statement it started notifying customers today, “which was within the required regulatory period.”

“This situation relates to rare occasions when both the Optus and Telstra networks are unavailable, and the phone needs to switch to Vodafone in order to contact emergency services,” it said.

“Impacted customers began receiving notifications today that their Samsung devices will be blocked within the next 28-35 days as is required by law.”

The ABC has contacted the regulator, the Australian Communications and Media Authority, for comment.

Editor’s note (22/10/2025): This article was updated after clarification from ACCAN about the estimated number of phone users potentially impacted. 

Devices that need to be replaced: