Update
On 23 April 2024, giffgaff announced they are working to actively migrate customers to their VoLTE and WiFi Calling stack. This will begin towards the end of April or start of May, and customers will be incrementally moved over the course of approximately 4 months.
Who's giffgaff?
giffgaff is a mobile virtual network operator, running on O2's network in the UK. They're a wholly owned subsidiary of Telefonica UK Limited, who trade as O2 UK.
Why do they not support some networking technologies?
We don't know! It might be technical limitations of their networking setup, or it could be restrictions put in place by O2 to draw more customers to their network instead. Noone can say for sure, except giffgaff.
Why is 4G calling so important?
Networks around the world are switching off their 2G and 3G networks,
with the USA being one of the first. The UK will follow suit over the
next few years, with Vodafone, Three and EE switching off 3G by the
end of 2023 2024.
Without support for Voice over LTE (VoLTE) on these networks, it is impossible to make calls. In some cases, this can also include calls to the emergency services.
The major networks in Britain have developed their VoLTE offering to the point where they offer VoLTE Roaming in multiple countries around the world. Yet some networks, such as giffgaff, have zero support for VoLTE whatsoever, and this should be a number one priority for them.
What are they missing?
Let's take a look!
| Tech | O2 | giffgaff |
|---|---|---|
| Voice over LTE (4G calling) | Yes source | No |
| WiFi calling | Yes source | No |
| 5G | Yes source | Yes source |
| eSIM | Yes source | Yes source |
| Visual Voicemail | Yes source | No |
| Smartwatches | Yes source | No |
| Free EU roaming | Yes source | Yes source |
| Voice over NR (5G calling) | No | No |