Apple has been forced to intervene after a software problem left some older iPhones unable to make standard or emergency calls on Telstra’s mobile network, adding to ongoing concerns about the reliability of Australia’s Triple Zero system.

As reported by the Australian Financial Review, the issue affected the iPhone 8, iPhone 8 Plus and iPhone X after a series of software updates released earlier in the week disrupted how the devices connected to Telstra, including their ability to place emergency calls. In response, Apple halted the updates while it worked on a fix.

The paused releases included iOS 18.7.4, iOS 16.7.13, iOS 15.8.6 and iOS 12.5.8. Although these updates had been tested by Telstra beforehand, changes to emergency calling technology caused unexpected compatibility problems once they reached customers. Apple reissued the updates on Thursday afternoon after resolving the fault.

Neither Apple nor Telstra would say how many Australians were affected during the disruption. Telstra said devices showing an “SOS calls” message were still able to connect to emergency services through alternative networks and added that it had not received reports of failed attempts to reach Triple Zero.

Apple said the problem was unrelated to earlier emergency call failures linked to the national shutdown of 3G networks, but did not provide further technical detail. Other telcos said the situation was unusual, with Optus noting it was not aware of any recent cases where a device manufacturer’s update had caused widespread call failures on its network.

The incident was not announced through formal media statements. Instead, customers were left to piece together information from company websites and Telstra’s social media posts. Apple also did not proactively notify media earlier in the week about separate connection issues affecting devices ranging from the iPhone SE to iPhone 12 models, along with several Apple Watch variants. Owners of those devices were advised to install updates to ensure phones could switch to alternative networks if their primary network failed.

The latest software problem comes amid heightened scrutiny of emergency call access following the closure of Australia’s 3G networks in 2024. Tens of thousands of handsets were affected by compatibility issues during the transition to 4G, with one death linked to a failed emergency call on the Vodafone network and another still under investigation.

Consumer advocates and politicians say confidence in the system has been badly shaken. Greens communications spokesperson Sarah Hanson-Young said the Triple Zero framework was struggling to keep pace with modern technology and failing to deliver a basic public safety service. The Australian Media and Communications Authority said it would review the latest incident to assess whether Apple and Telstra met their legal obligations.

Carol Bennett, chief executive of the Australian Communications Consumer Action Network, said repeated outages, unclear messaging and device compatibility problems had eroded trust. She warned that issues seen during last year’s 3G shutdown were continuing into this year, leaving consumers confused and exposed.

Australia’s major telcos have repeatedly warned customers over the past year that some Samsung and Apple devices need software updates or replacement to ensure emergency calls work correctly on 4G networks. Unlike 3G, 4G does not operate under a single global standard, meaning each network has its own technical variations. That complexity places greater responsibility on device makers to ensure their phones function reliably across all networks, particularly when it comes to accessing emergency services.