The phone has no message but has a light blinking. I have her dial *40 to inquire message waiting but it gives me a not valid. How do I clear this message with out deleting the ext.

so She does *40 then ext number and it says message waiting at the top then it does not give any options.

Any ideas on this?

You may have to check the correct feature access code for your system. You are looking for Message waiting deactivate. Then dial the code plus the ext number that you want turned off. You should be able to do it from the user's phone itself.

You may also need to call voicemail, leave an extension for the mailbox, and then delete the message.