How do I change the caller ID on the grandstream phone
As before, you need to provide more detail.
Posting a one line statement without any context provides no insight. While the question may seem like a simple one, without knowing more of how you use it, what it is connected to, if you use SIP trunking or PSTN for your provider, etc., doesn’t allow us to provide any educated guidance towards a solution.
It’s like saying “I have a headache, how can I get rid of it”? There could be any number or reasons of why I have one and aspirin may not always be the fix.
The caller ID can be controlled via the extension, the system, or the provider.
So, depending on the setup, you might not have any direct control.