HTC One S

Find "Call forwarding"

Press the menu icon.

Find "Call forwarding"

Press Settings.

Find "Call forwarding"

Press Call.

Find "Call forwarding"

Press Call forwarding.

Select divert type

The current settings will be displayed.

Select divert type

Press one of the following options:
Always forward

Select divert type

Forward when busy

Select divert type

Forward when unanswered

Select divert type

Forward when unreachable

Divert calls to voicemail

Key in (prefix) 5 (your phone number)
If you selected Forward when unanswered in step 2.

Divert calls to voicemail

Press the field below Delay.

Divert calls to voicemail

Press the required delay.

Divert calls to voicemail

Press Enable.

Exit

Press the Home key to return to standby mode.