Calling Line Identification. . The ability to see who is calling you before answering the phone. It will store the telephone numbers of historic callers, which means where messages have been taken with incorrect telephone numbers you can still retrieve the correct number from your system. Also calls can be automatically routed directly to the correct department, such as accounts queries straight to accounts.
CLI has to be switched on by your line network provider who will charge a small rental fee. The amount can vary depending on who your provider is.