Oppo (and Realme) devices use a strict verification process for bootloader unlocking. The "Serial Not Match" error typically triggers for three reasons:
The error essentially means there is a security mismatch between the unlock token (or command) you are sending and what the device’s hardware expects. Why Does This Error Occur? the serial is not match fastboot unlock verify fail oppo
If you are using a Chinese ROM, the global Deep Testing APK will almost always return a "Serial Not Match" error. You must use the Chinese version of the app linked to an OPPO ID registered in that region. Important Reminder Oppo (and Realme) devices use a strict verification
If your PC sees the device as a "Marshall London Bootloader" or a generic "Android Device," the serial verification will fail. If you are using a Chinese ROM, the
Your PC is communicating with the phone using generic drivers that misinterpret the serial string in Fastboot mode. Step-by-Step Solutions 1. Verify the "Deep Testing" App Version
Many users see "Review Successful" in the app and immediately jump into Fastboot. However, it can take time for the device's internal flag to sync with the server’s approval.
Ensure the APK version matches your Android version (e.g., don't use an Android 11 unlock tool on Android 13). Check forums like XDA Developers for the specific version for your exact model number (e.g., CPH2023). 2. The "Wait and Sync" Method