How To Turn Off O2 Voicemail 3 Working Methods

If your voicemail was not turned off, try using the Android or iPhone method for disabling your voicemail manually. You can re-dial 1760 to turn your voicemail back on. If you previously had, or still have, the app TuGo on your device, it may prevent you from turning off your voicemail. To fix this, open the app on your phone (re-download it if necessary) and go to Settings > Turn off Voicemail. [1] X Research source

If it still has not turned off, try the steps to call 404 again before getting in touch with O2 customer support.

Alternatively, you can go to Settings > Apps > More Settings > Disable Forward (next to “When Unanswered, when busy, and When Unreached).