Tap on seven times until a toast notification says "You are now a developer."

Power off your device. Hold the Volume Up button while connecting it to your PC via USB to enter Fastboot mode (the LED should turn blue). Open a command prompt and type: fastboot oem unlock 0xYOUR_UNLOCK_CODE . 2. Alternative Tools (Third-Party)

Not all Sony Xperia devices can be unlocked. Some carrier-branded models lock this feature permanently. Open the phone dialer on your Xperia device. Enter the code: *#*#7378423#*#* to open the service menu. Tap on > Configuration > Rooting Status . Look for Bootloader unlock allowed . If it says Yes , you can proceed. If it says No , your device's bootloader cannot be unlocked. Step 2: Get the Unique Unlock Code from Sony

Once you have downloaded the tools and secured your code, you are ready to execute the unlock. Phase A: Put Your Sony Phone into Fastboot Mode Turn off your Sony Xperia device completely. Hold down the button.

Sony explicitly states that unlocking the bootloader voids your manufacturer warranty.

For developers and advanced users looking to install custom ROMs or firmware, Sony provides an official Unlock Bootloader service Verify Compatibility: Before starting, enter *#*#7378423#*#* in your phone's dialer, go to Service info Configuration Rooting Status . It must say "Bootloader unlock allowed: Yes." Get the Unlock Code: You will need to provide your device's IMEI to the Sony Developer portal to receive a unique unlock key. Flash Tool: You will typically use the standard