/* Disclaimer */
This is at your own risk.
I am not responsible for broken phones, lost IMEI numbers, damaged EFS partition, whatever.
First make a backup of the EFS partition via TWRP or ADB, and back it up to a safe place on your computer!
WARNING: The EFS partition contains unique data for your device that is necessary for the phone function of your device. If you lose them, no one can help you out. So make a backup. If something goes wrong, you can restore the backup and you will be back to its original state.
2. you go to your computer and install both.
Qualcomm QPST Diag x64 driver
QPST_2.7.420
Now connect your mobile phone to your computer via a "USB cable".
4. opens the phone app and enter this code *#801#.
Now a new menu appears and switches "Serial" and "Full-port switch" on.
Now you start the program: "QPST Software Download" and connect it to your device.
Go to the "MCFG_PDC" tab at the top and select your device under "Device:".
Right-click on "Oversea-Commercial_DS" and select "Sub0" and "Sub1" under "Deactivate".
Now click on "Oversea-Commercial_DS" again and click on "Remove" on the right.
Now restart the program and go to the tab "MCFG_PDC" and under "Device:" select your device again.
Now select "Telefonica_UK_Commercial", right click and select "SetSelectedConfig" "Sub0" and "Sub1".
12. click on "Telefonica_UK_Commercial" then right click on "Activate" and then on "Start" below
13. after you have done everything, restart the device!
After a successful restart, the "VoLTE or VoWiFi logo" should appear in the expanded status bar.
No wonder why you dial "Telefonica_UK_Commercial", works great in Germany with all providers!
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