At times, you may need to set up call forwarding to an external phone number ( like a mobile number) from OnSIP.

First, you will need to create an External Phone Number under Outbound Settings within app.onsip.com as the Admin. 

If you would like an OnSIP phone number to forward to the newly created External Phone Number, go to Phone numbers, choose the number you are wanting to forward then "Edit info". Under the Destination, choose the "x" to remove the current destination, then in the search bar locate the newly created External Phone Number and "Save changes". This will take effect immediately.

If the forward needs to be for one User only, then go to Users, click to expand the options and under the Call Settings tab choose "Edit info" and change the "Failover to" to the newly created External Phone Number. Then "Save changes".