What is “TEL” on a Fax Machine?

LAST UPDATE: June 5th, 2019

Definition

“TEL” on a fax machine or fax modem can be:

  1. The port to connect a telephone handset to a fax to enable it as a telephone.
  2. The port connects to the fax to a phone jack (sometimes labeled “LINE“).
  3. The port connects an extension telephone to the fax (sometimes labeled “EXT“).
  4. In the context of “FAX/TEL,” a switch that changes between fax and telephone modes.
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.

Usage

A “TEL” port is used to connect either the fax machine’s telephone handset or to add an extension telephone so that there can be a fax machine and another telephone on the line.

If there is one port for a phone line labeled “TEL,” it is for the landline phone line.

If there are two ports, one of which is labeled “TEL”…

  • … and the other “EXT,” then the “TEL” port is to connect the fax to the phone line, and the “EXT” port for an extension telephone.
  • … and the other “LINE,” then the “LINE” port is for the telephone jack, and the “TEL” port is to connect an extension telephone (an extra phone that can use the same line) or the fax’s telephone handset.

If there are three ports, one of which is labeled “TEL” and the others “EXT” and “LINE,” the “TEL” port is for a telephone handset.

Similar Terms

The “TEL” port can be confused with the “EXT” (for an extension telephone) and “LINE” (to connect to a landline phone line) ports.

Sources and more resources