Is your device from overseas or second hand? 

If you’re using a device that was set up for another country (i.e. you bought it overseas, it was imported, or it’s second-hand and you’re not sure where it’s from), it may have patchy coverage when 3G closes. 

That’s because Telstra’s main 4G frequency is band 28 (B28)/700MHz. But in many countries, this frequency isn’t used for 4G, so phones aren’t configured to use it. 

You can find out if your phone is in this category by texting ‘3’ to 3498. If it is, you’ll need to upgrade to avoid losing coverage in places where B28 is the only available frequency (usually outside major cities/regional hubs).