From time to time you may need to add or remove extensions from your system. This may include direct numbers. For our 3CX systems, you can self manage this to find out more, please have a read of our Extension management through the management console article. This article provides a bit of information into what happens when an extension is removed.
Removing an extension
Once a request has come in to remove an extension we will reply ensuring that we have the correct extension and any direct numbers that you would like to remove. This is important as you may like to release the direct number, doing so, we may not be able to recover this as it is marked available in our carrier list.
Once it is verified that you would like to remove the extension listed, we would remove the resource and let you know this has been completed. One thing that is important to note if they had a physical phone is that the phone will continue to send a request to the server to authenticate the extension, this can lead to your network being blacklisted due to incorrect login attempts. We would strongly recommend removing the credentials from any softphone and factory resetting or unplugging and device that is not in use which may store old credentials.
If the above steps did not resolve your issue, you can raise a case with our team by clicking here. We may verify that you have completed the above steps, so don't forget to try!