These are the steps that need to be followed in order for an extension to send an alternate caller ID.
You must ensure that you have requested the tenant CLI to be opened up at the tenant level. This is done by emailing support@cloudkinnet.com.au. Without this any CLI set will be over stamped with the tenant default.
To set the CLI for the extension
Navigate to the desired extension
Click Enhanced Services
Enable Caller ID (Click on the 'tick')
Click Save
Click the Edit Caller ID button
Enter the desired caller ID as per the below screenshot
Click Save