AI has now suggested this - any thoughts anyone?
a corrupted profile on the Home Location Register (HLR) is a highly likely technical reason why your phone stopped working, but a major network change in Switzerland that occurred in May 2026 is the ultimate trigger.
[1]
The Root Cause: Switzerland's 3G Switch-Off
In
May 2026, major Swiss telecom operators (such as Swisscom) completed the final phases of
shutting down their legacy 3G networks. Switzerland had already deactivated 2G in 2021.
[1, 2, 3, 4, 5]When a foreign country shuts down its 3G network, your UK phone must rely on
VoLTE (Voice over LTE) Roaming to route phone calls and texts over local 4G/5G infrastructure. If your BT Mobile account profile inside the HLR hasn't been updated to handle 4G/5G data handshakes or VoLTE roaming with Swiss networks,
your phone will experience a complete block on service.
[1, 2, 3]Because Switzerland is still technically included in BT's
Roam Like Home Zone 1b policy, the issue is not a change in your plan's pricing, but a technical disconnect between BT's backend and the modern Swiss towers
How to Fix It
1. Contact BT for an HLR / Provisioning Reset
Call BT customer service and tell them:
"I am roaming in Switzerland where 3G has been switched off. My phone will not connect. Please refresh my HLR profile and ensure VoLTE Roaming and Data Roaming are fully re-provisioned on my account." [1, 2, 3, 4]
