Enable Developer Options on Sony Xperia Z Ultra

1. Head into the Settings menu;

2. Now, scroll down to and select the Software information selection;

3. You will see there an option called Build number ? this is what you’ll need to tap;

4. From here, just quickly tap Build number a few times and it will unlock the developer menu. After a few taps you’ll see a prompt on-screen that confirms the fact that you are just a few steps away, so tap a few more times and that’s it. You should see a new popup that states you’re now a developer;

5. To find Developer Options, go back to Settings and they should now be on the list of options.

Now, you can check the USB debugging box under Developer options, so you have successfully enabled Sony’s Xperia Z Ultra USB debugging as well!

[출처 : http://androidflagship.com/25472-enable-developer-options-on-sony-xperia-z-ultra]