It is possible to divert or forward calls to an external telephone number (a home or a mobile number).
To set up an external number, navigate to the Users & Extensions section in your control panel (as below).
Click 'Add new' then 'External number'
You can configure the external number as below. You need to give your external number a familiar name and enter the external number itself (it can be a home phone or mobile) and then click Create External Number.
Your external number has now been created.
You can set your Gradwell telephone number to forward calls to your external number from the Phone Numbers page.
On the Phone Numbers page, click the Edit button next to the phone number that you wish to change the destination for, and then select your external number from the drop-down list and click Save.