Find this 15-digit code on the sticker at the bottom of the device or in the web settings under "Device Information."
The carrier will send you an 8-digit or 16-digit network unlock code (NUC) via email or SMS. Method 2: Using Professional Unlocking Services Unlock Huawei B311-221
Unlocking your device via third-party software or firmware flashing may void your manufacturer's warranty. Troubleshooting Common Issues Find this 15-digit code on the sticker at