While setting up users through the management console you are also able to enter in their inbound routes as their caller ID. To set this up please follow the below settings
Adding an extension
Under the User Information tab in the general settings, you have the ability to enter in an Outbound Caller ID as shown below
Once you have assigned or know of the inbound number for this specific extension you can enter this here. For example, you own 0212345678 and would like to assign this inbound route to this extension. Under Outbound Caller ID you would enter +61212345678.
If you do not have access to the management console and require access, please reach out to our support team here