Important Note: This information only applies to our physical Voice+Data SIM Card product.
If you are using a Xiaomi handset and you are unable to place / receive calls (but all other services are working correctly), we would firstly recommend that you check the information found here: VoLTE Troubleshooting Guide
If the issue persists however, you may be required to force enable the VoLTE feature on your device (to allow VoLTE calls to be placed via the Softbank network).
In most cases, this can be resolved by dialing the following number from the keypad: *#*#86583#*#*
You should then see a “VoLTE carrier check was disabled” message or a “VoLTE carrier check was enabled” message after dialing the code.
This can lead to some confusion but to allow VoLTE calls, you must ensure the “VoLTE carrier check was disabled” message is displayed.
If you see a message stating that the carrier check was “enabled”, this is incorrect and so please dial this code again until you see the “VoLTE carrier check was disabled” message.
Once you have seen this message, please test the calling feature again and if there is no change, reboot your device and then test the calling feature again after a few minutes.