What is a Phone Line Key?

A phone line key is one of the keys used to designate individual lines on a phone. Depending on the model and manufacturer, phones typically have between two and 12 phone line keys.

When utilizing line mirroring, you can use these keys to manage multiple calls that you have accepted with call waiting.

The Busy Lamp field uses phone line keys to monitor other phones. These line keys can be used as speed dials.