Updating SIM card to 5G

[Ant2011]

I have a SIM only contract and my SIM is a couple of years old so doesn't support 5G. I've recently bought a new handset (Samsung Galaxy S21) which does support 5G and I'd like to take advantage of it as there is 5G coverage in my area. I have a few questions for anyone who has upgraded their BT SIM to 5G.

1. Will BT send out a new 5G compatible SIM without me having to change my contract, or do I have to start a new contract and change to one of the currently available deals?
2. 4G has VoLTE to allow high quality phone calls over the 4G internet connection. Does 5G have something similar and do the BT SIMs support it?
3. Do the latest 5G BT SIMs still support WiFi calling? That works on my old 4G SIM at the moment and I find it very useful.

Thanks in advance!

[Graham18 · Accepted solution]

I too have a SIM only contract, and recently got a Samsung A52 5G phone.

I signed up for a new contract that included 5G. No new SIM required, 5G was working within minutes of agreeing the new contract

Wifi calling and VoLTE both work.

[Ant2011]

Thanks.

I assume your SIM was already 5G capable, mine is a couple of years old at least so may not be. My contract is as old as that too so I'm not sure if it will include 5G as is, or if I will need a new contract.

It looks like there is a better deal available at the moment than the one I have, so I'll probably just switch to a new contract anyway.

[Ant2011]

I can confirm a new contract was needed in my case. BT did tell me I needed a new SIM, so I waited until I'd received it before doing anything about changing contract. But with the new SIM installed and activated there was no difference, still no sign of 5G. BT subsequently told me my current package didn't support it. As soon as I signed up for a new package, my phone began connecting to 5G.

I'm curious as to how voice calls are handled with 5G. The phone still shows VoLTE when 5G is active, but I thought LTE was a 4G technology. Does this mean it's still using 4G for voice calls at the same time as 5G for data or does 5G support voice calls directly using the same system?