We are working with Optus to make some changes to the 3G network, to future proof the 4G and 5G network experience for our customers.

This change may be a little disruptive for some customers. However, we’re here to help you along the way to make the transition as smooth as possible.


From September 2024, Optus will begin repurposing (re-farming) the 900MHz spectrum to provide a better 4G network experience as well as to support the growth of 5G technology. This is an important action to ensure customers have access to the very best network experience that can be provided.

This 900MHz re-farm follows the 2100MHz re-farm that was completed in 2022.

Once the re-farm of 900MHz spectrum commences in September 2024, 3G services will no longer be available on the Optus network.

Update: To remind you to upgrade your phone, from mid-July, in the lead up to the switch off, you will hear a pre-recorded message and receive a SMS when you make the first call of the day.


Any device that relies upon 3G will be impacted by the upcoming changes. This means that some devices will no longer be compatible with the Optus mobile network and customers with these devices might experience disruptions with their amaysim service beyond September 2024.

We will be contacting customers we believe may be impacted well in advance of the change date.


Most phones recently purchased or for sale in Australia will be able to continue accessing the Optus mobile network. If you have an older device or think you may be impacted, it is important to check your device specifications to make sure it will remain compatible.

You should check that your device supports the following to ensure ongoing network compatibility:

  • 4G 700 MHz (LTE Band 28)
  • Voice over LTE (VoLTE)

Device specific compatibility information should be available on your device manufacturers website by checking the specification guide of your respective device.

In most cases, frequency information will be located under a section titled Mobile and Wireless or Networks & Connectivity, and VoLTE under Audio Calling or Voice features.

If you’re unable to find the correct information for your device online you’ll need to contact your device manufacturer directly.

If you were using an iPhone SE, you’d head to Apple’s website and view the specifications guide of the device, making sure the frequencies above were listed on the specs guide.

In this instance, the iPhone SE would remain compatible, as the 700 MHZ (LTE Band 28) is listed on the specs guide under the Mobile and Wireless section, and VoLTE is listed under Audio Calling.


If your device is no longer compatible, you can purchase a new compatible device to avoid any disruptions to your amaysim service or change providers.

We strongly recommend purchasing a 4G VoLTE compatible device to future proof your mobile experience.

Most phones available today or sold recently in Australia fully support the Optus Mobile Network. Here are some examples:

  • Apple iPhone SE, iPhone 6 and newer (minimum iOS 10.2.1)
  • Samsung Galaxy S10, and newer
  • Google Pixel 3 and newer
  • LG G5, HTC 10 & U11, Sony Xperia XZ
  • Nokia 225 4G, Optus X Lite 4G


If you’re unsure if your device will be impacted or have questions about how this change may impact your amaysim service, please contact our customer service team who will be more than happy to assist.

Some 4G phones will use 3G to make voice calls, emergency calls, and to achieve maximum coverage. This affects mainly older phones and those not designed for Australia. If your phone does not support VoLTE and 4G 700MHz, you should upgrade before 3G is switched off.

This is important to ensure you have the best coverage. There are several different frequencies used for 4G, with 700MHz (LTE Band 28) being the one in most places and providing the widest coverage.

This is important to ensure your phone can make voice calls and emergency calls on 4G. You may have heard of VoIP for your home phone and NBN. VoLTE is a similar thing but for mobile and allows your phone to make a voice call on 4G. You might see it called HD Voice elsewhere. If your phone does not support VoLTE, you should upgrade before 3G is switched off.

 Yes. Optus (which provides the network for your amaysim service) will no longer operate a 3G network after September 2024.

A 5G phone will still use 4G to make VoLTE phone calls. Most 5G phones sold in Australia will also support 4G, and you should still look for 4G 700 MHz (Band 28) compatibility.