Steps to unlock bootloader on Xiaomi 12

To enter the process of unlocking, you are required to enable the developer option first and then OEM unlock.

• Go to Settings » About phone » MIUI version.
• Tap repeatedly on the MIUI version until you see the pop-up You are now a developer!

• Go back to Settings, click on Additional settings, then Developer options.
• Enable OEM unlocking and USB debugging.
• Bind your Xiaomi account to your Xiaomi 12. Tap Mi Unlock status » Agree » Add account and device. Make sure your device can connect to the internet using mobile data.

• Once the account is successfully bound, you should get a message Added successfully. Mi account is associated with this device now.
• Now turn off your phone, press and hold the Volume Down key and the Power button to enter Fastboot mode.
• Connect your phone to PC using USB cable.
• Download and launch the Mi Unlock on your PC and sign in to your Xiaomi account (Email/Phone/Xiaomi Account and Password). Make sure your phone is in Fastboot mode and connected to PC.

• The server will check whether the Xiaomi account is bound to your phone or not.
• You have already done that on the phone, so you should get Phone connected message on Mi Unlock. If you get Not connected to the phone message, reinstall Mi USB driver and try again.
• Click on Unlock » Unlock anyway. On your first attempt, Mi Unlock will flash the message Couldn’t unlock. Please unlock 168 hours later. Follow the timer / waiting period to unlock successfully.

• Once the bootloader is unlocked, your phone should reboot automatically. If it doesn't, click on Reboot phone.

• Congrats, you have successfully unlocked the bootloader on the Xiaomi 12.