OnePlus 9 Pro - Bootloader Unlock

Step 1. Install Android tools

The same thing can be done on Mac, Windows or Linux withandroid-platform-tools installed.

# Install Android tools on Mac with Homebrew
brew install --cask android-platform-tools

Step 2. Enable OEM Unlocking on OnePlus 9 Pro

1. Go to Settings > About Phone > Tap on Build number 5-6 times to enable Developer options.
2. Now go to > System > Developer options > enable OEM Unlocking and USB debugging.
3. Make sure your PC is authorized when you plugin the USB cable.

Step 3. Get your IMEI

Get your phone’s IMEI by dialing *#06# in the phone’s dialer. The IMEI code will show up. You will need this for T-Mobile’s form later on.

Step 4. Get your unlock code

1. Reboot into fastboot mode

adb reboot bootloader

1. Generate Unlock code for T-Mobile’s online form.

fastboot oem get_unlock_code

# Example what it looks like
MacBook:~$ fastboot oem get_unlock_code
(bootloader) Serial Number:
(bootloader) ====================================
(bootloader) 3dxxxx26
(bootloader) ====================================
(bootloader) Unlock code:
(bootloader) ====================================
(bootloader) 8B9D3B46A02677526B7953A8A2XXXXXX
(bootloader) 00F5147972F8B93DCA6E7B8AC3XXXXXX
(bootloader) ====================================

1. Combine the 2 lines into one long string

Example Unlock code:

8B9D3B46A02677526B7953A8A2F6356700F5147972F8B93DCA6E7B8AC3XXXXXX

Step 5. Fill out the T-Mobile online form

This is where you will need to enter your IMEI code and your unlock code (2 lines as one long code). Once you submit it, you should receive a flashable unlock token within two weeks.

https://www.oneplus.com/unlock_token

Step 6. OEM Bootloader Unlock

Warning! Unlocking the bootloader will reset/erase your device. Back up first if anything important.

1. Reboot in Fastboot mode

adb reboot bootloader

1. Flash the Unlock token bin

fastboot flash cust-unlock unlock_code.bin 

Sending 'cust-unlock' (0 KB)                       OKAY [  0.002s]
Writing 'cust-unlock'                              (bootloader) Device is unlocked.
OKAY [  0.003s]
Finished. Total time: 0.015s

1. Unlock the bootloader

fastboot oem unlock

OKAY [  0.034s]
Finished. Total time: 0.034s

References

Guides:

https://www.oneplus.com/support/answer/detail/op588

Unbrick

https://forum.xda-developers.com/t/op9pro-repository-of-msm-unbrick-tools-tmo-eu-glo-in.4272549/

https://onepluscommunityserver.com/list/Unbrick_Tools/OnePlus_9_Pro

OEM Unlocking Grayed out

https://www.droidwin.com/enable-greyed-out-oem-unlock-in-oneplus-carrier-locked-t-mobile/#How_to_Enable_Greyed_out_OEM_Unlock_in_OnePlus_Carrier_Locked_T-Mobile