Find "Voice call"
Press the phone icon.
Press Keypad.
Press the menu icon.
Press Settings.
Press Call.
Press Additional settings.
After a moment the current settings are displayed.
After a moment the current settings are displayed.
Press Call forwarding.
Press Voice call.
Select divert type
The current settings are displayed.
Press one of the following options:
Always forward
Always forward
Forward when busy
Forward when unanswered
Forward when unreachable
Divert calls to voicemail
Key in (prefix) 5 (your phone number) and press Enable.
Return to the home screen
Press the Home key to return to the home screen.