When attempting to change extension numbers in Account Manager, you get an error message saying the extension is already in use, even though the desired numbers appear available.
This error is easily resolved by a consultation with our Tech Support team. To contact 8x8 Technical Support, log in to create a case.
This can happen if you have ever closed out a line of service without changing out the extension number associated with it. Though rare, it can trick the system into the thinking the extension is actually still in use.