What is “LINE” on a Fax Machine?

LAST UPDATE: June 5th, 2019


‘LINE’ on a fax machine is a port to connect the fax machine to a landline phone line.

It is found on its own or near an ‘EXT‘ port (used to connect a phone extension).

Image of a fax machine connected to: 1 - an extension telephone (marked "EXT" or "TEL"), 2 - a landline phone jack (marked "EXT"), and 3 - a telephone handset (marked "TEL")
The “LINE” port is connected to a landline phone line. The “EXT” and “TEL” ports connect to an extension telephone. If there are three ports, the “TEL” port connects to the fax machine’s telephone handset.


Fax machines and fax modems have a ‘LINE’ port to connect the fax to a landline phone jack.

A landline phone connection is required to use the fax machine.

Plugging the fax machine into the phone line is part of setting up a fax machine.

Some fax machines have line ports numerically labeled (LINE 1, LINE 2, LINE 3). These fax machines have multiple lines. Connect the first line to LINE 1, and any extra lines in numerical order.

Similar Terms

Sometimes the “LINE” port is confused with ports labeled “EXT” and “TEL.”

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