Customer update: Triple Zero and Samsung Devices

During emergencies, and at times when your mobile phone can’t connect to its regular network, your phone is designed to search for another available network to reach Triple Zero.  
 
However, Optus and some other telco carriers have recently identified some Samsung mobile devices that will not connect to Triple Zero in certain circumstances. 
 
These situations relate 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.  
 
This issue does not relate to the Optus network - it will not affect your ability to call Triple Zero when you are using the Optus network or the Telstra network.  
 
And this only happens under very specific conditions, but it’s critically important that all devices can reach Triple Zero. 
 
Importantly, we have started contacting customers whose phones are affected with instructions on what to do next to ensure their phones work when they need them most. 
 
These impacted devices need to be replaced to ensure they can reach Triple Zero during an emergency.  
 
To help keep the community safe, all identified devices will be blocked by Optus from between 28 to 35 days after customers are notified. 
 
Optus conducts monthly reviews of devices connected to its network to verify that they satisfy emergency call requirements. Optus has regulatory and legal obligations to block devices from its network that do not meet these requirements and impacted customers will start to receive SMS and email notifications from 22 October 2025.  
 
Roaming customers that come into Australia and are using a blocked device will not be able to connect to the Optus network. 
 
Customers can check below whether their device is affected or contact our customer service team on 133 937 for further information or assistance.

The following devices will be blocked from between 28 - 35 days after you have been notified and need to be replaced. 

Why is this happening? 
Some phones don’t automatically switch to another network when needed. This means they might not be able to call Triple Zero in an emergency if your usual network isn’t working. 
 
Does this affect all mobile phones? 
Only specific models are impacted - not all Samsung phones. You will receive an SMS or email notification from us from 22 October 2025 if your mobile device is impacted. 
 
What is the issue? 
Certain older Samsung devices do not support automatic fallback (‘camp-on’) to the Vodafone network on rare occasions when both Optus and Telstra networks are down. This is a requirement by law to ensure Triple Zero calls can be made when your primary network is unavailable. 
 
Which devices are affected? 
Optus has identified some older Samsung mobile handsets that are/or have been connected to our network that will not camp-on to the TPG/Vodafone network if both Optus and Telstra networks are down. The list can be found above.  
 
Can this issue be fixed? 
No. These devices that will be blocked after the 28 - 35 calendar day notice period will not work on our network.  
 
How will I know if my device is impacted? 
We’re contacting affected customers via SMS and email. You can also check your device status on the Optus website www.optus.com.au or call our customer service team on 133 937.  
 
What happens if I don’t act? 
Under the Emergency Call Services Determination (ECSD), Optus must notify customers within five business days of identifying a non-compliant device. Devices must then be blocked within 28 - 35 calendar days. Once blocked, your device will no longer be able to make or receive calls, send texts, or use mobile data. 
 
Can I still use Wi-Fi? 
Blocked devices cannot make voice calls over Wi-Fi, including emergency calls, or send/receive SMS. 
 
Why does this happen? 
Differences in device software, firmware, and network compatibility can affect whether an emergency call connects successfully. Some devices don’t behave consistently under network stress or configuration changes, and this can vary depending on the phone’s country of origin. 
 
What is Optus doing about it? 
We conduct monthly reviews of all devices connected to our network to verify emergency call compliance. We are working with industry to ensure rigorous device testing.