When I went to a Telstra store late last month to move the service from my physical SIM to the iPhone 12 Pro Max's eSIM, I was surprised to be told that using two SIMs at the same time meant that I was going to be stuck on 4G only.
At first, my initial response was to simply refuse to believe it, but a quick Google search showed that it was, in fact, true. At the time.
You can see for yourself at this Telstra Crowdsupport document which states "Due to a limitation across the iPhone 12 family, you won't be able to use 5G if you have Dual SIM enabled. This issue isn't unique to Telstra. To access 5G, you'll need to disable your secondary mobile service."
The document went on to state that "When using two lines in Dual SIM mode, 5G data isn’t supported on either line and will fall back to 4G LTE. If you are using eSIM or physical SIM only and are on a 5G-supported carrier and service plan, you’ll have 5G access", and the "fix" was to either temporarily turn off the eSIM line or eject the physical SIM so that only one SIM with 5G was active, and then 5G could be used.
So, it was great to see in the iOS 14.5 update text that the new OS included three 5G improvements, which are as follows:
- Dual SIM support enables 5G connectivity on the line that's using cellular data on iPhone 12 models
- Smart Data Mode improvements further optimise your experience on 5G networks for better battery life and data usage on iPhone 12 models
- 5G international roaming enabled on supported carriers on iPhone 12 models
The next step was to test if this was the case for us in Australia, and I can confirm that it definitely is!
I have 5G on Telstra, and also 5G on Vodafone. The suburb I'm in has 5G for Telstra, but there's no 5G for Vodafone yet.
My eSIM is on Telstra, so I popped in the Vodafone physical SIM, turned 5G on for my eSIM, and as you can see from the photo above, I have two lines connected, and the 5G symbol appears.
So, now you can have your 5G cake and eat it, too, but whether you can have 5G active on BOTH SIMs at the same time (especially given iPhones allow "cellular switching") is something I'll check later today when I'm in a Vodafone 5G signal area.