This feature is available only in the USA and Canada.

The two telephone numbers can be on separate jacks (RJ11) or combined into one jack (RJ14). Your machine must be plugged into an RJ11 jack. RJ11 and RJ14 jacks may be equal in size and appearance and both may contain four wires (black, red, green, yellow). To test the type of jack, plug in a two-line telephone and see if it can access both lines. If it can access both lines, you must separate the line for your machine.