Please make sure that you have not set your VoIP line to go to voicemail for the call forwarding options for 'On busy' or 'No answer' (as shown in the example below) as this does not need to be done as this is automatic if the call is not answered or the line is busy it will go to voicemail.
The call forwarding option for 'On busy' or 'No answer' is to be used if you want to divert to a different number only by using the 'Transfer to number' option as shown in the example below:
Make sure you enter the number to transfer to without any spaces.
As standard your phone will ring for 20 rings before going to voicemail, however If you want to shorten the amount of time that your phone rings before it goes to voicemail please click here to see how.