Why use WiFi calling
On the one hand, WiFi calling is the cheapest way to keep a number active. On the other hand, many UK mobile numbers have roaming restrictions. To avoid problems, it is necessary to use WiFi calling while disguising your location as being in the UK.
What you need
- Devices
I think using a software router/router still requires a certain level of technical skill.
So I recommend simply enabling global TUN mode on a computer and turning on its hotspot for your phone to connect to.
Although this is less convenient, it is easier. - Nodes
Many people recommend clean UK residential IPs.
But in fact, I also succeeded using a datacenter IP of fairly poor quality (with Voxi, Lebara, and a previous £1 CMLink physical SIM).
In other words, an AWS datacenter IP alone is enough. For the node, I used this open-source project.
(Theoretically, anything that supports UDP forwarding should work. In Clash Verge, you can see whether each node supports forwarding—but the proxy nodes from a subscription I used previously did not work, even though their IP quality was better than that of datacenter IPs and they were also shown as supporting UDP forwarding. I have no idea why.)
AWS, as a cloud provider where you can get $200 for free, is also relatively easy to access (it seems you can open an account with a UnionPay card now). So you could say that no special preparation is required.
具体操作
(I’m only describing what I did. I don’t know whether other methods would work, or whether other devices would work—I haven’t planned to switch devices and try.)
I used a Hong Kong version of the Samsung S25 with an external Xesim card/CMLink physical SIM.
First, remove the physical SIM/disable the external card (don’t enable any eSIM).
Enable virtual location (fake GPS).
Turn on airplane mode.
Connect to the computer’s UK hotspot.
Once you’ve confirmed that it is connected, insert the SIM/turn on the eSIM switch.
Wait about one minute.
(I used these two: Tuic/Hysteria2. If nothing happens after waiting for a while after switching SIMs, try changing the protocol or re-enabling the WiFi calling button.)
The following will appear:
Registering for GPT usually means receiving the verification code almost instantly. Once you receive the code, it has worked.
Other
Some SIMs, such as Asda and Lebara, are more sensitive (or have some issues).
It is recommended not to connect to mainland Chinese cellular networks. WiFi calling works fine anyway. If you connect to a cellular network, it might end up like giffgaff—if they happen to be in a bad mood one day, they could terminate everything for you.
Maintain a UK environment throughout the entire process, from downloading and using it to disabling the eSIM/removing the physical SIM.