How to Hook Up a Fax Machine

By David Weedmark

Updated November 09, 2019

Hook Up a Fax Machine

Believe it or not, fax machines were once a sign of a busy modern office. While faxes (short for facsimiles) are far less common than they used to be, they still have their benefits. Faxing is still considered a more secure option for sending documents than putting them in the mail, and it can be a good alternative if your emails, text attachments, instant message attachments or shared folder links just aren’t getting through.


Although every model can vary in its setup, hooking up a fax machine shouldn’t be complicated. Generally speaking, any place you can connect a wired phone, you can also connect a fax machine.

Connecting a Fax Machine and Phone on the Same Line

If you plan to send and receive faxes on a regular basis, having a second phone line just for the fax machine is something to consider. Many businesses do this using two lines: one fax machine number and one phone number. This, however, isn't mandatory. You can connect your fax machine to your single phone line just as you can connect more than one phone to that line.

All you need is a spare telephone jack. If you don't have one, you have two options. You can get a telephone line splitter (or phone/fax splitter), which connects to the jack and allows you to connect your phone and fax machine to it. The second option is to disconnect your telephone while you are sending a fax or when you are about to receive one.

The biggest problem you'll face when using a fax machine on your phone line is that when the phone rings, you won't know if it's a fax coming in or a person calling until you pick up the phone. If you hear a buzzy-squeaky noise, that's a fax, so hang up and don't answer the phone when it rings again. The fax machine will automatically call again after a few seconds.

Connecting the Fax to an RJ-11 Connector

In most cases, a fax machine uses the same connector as a home or office telephone: an RJ-11 connector. You'll need a cord to connect the fax machine to an outlet, which should have come with your fax machine. The ends of the cord should have a plastic cap with a squeezable lever that's used to lock it into the adapter. You should see two copper wires at the end of the connector.

Connect one end to the fax machine and the other end to any working telephone jack. The connector on the fax machine should say "Line" or "r-Line" or may just have a telephone symbol on it. When you connect the cord, it should snap easily into place. Network cables have similar RJ-45 connectors but are larger than RJ-11 connectors. If you're not certain if a phone jack is working, connect a phone to it to test it.

Fax Using Cable Internet or Fiber Internet

Many homes and offices today no longer use traditional phone lines and have their telephones connected to their cable internet or fiber internet service. If your service has a dedicated phone box, you should be able to connect your fax machine to it just as you would a telephone. If your service has been wired to your internal phone lines and your phones are connected to the wall jacks, connect your fax machine to any working wall jack.

In some cases, you may have issues. Older fax machines may not work properly if they were made before VoIP services were introduced. Additionally, your service provider may limit some usage of your fax machine. Google Fiber, for example, warns its customers that if a fax is longer than 20 or 30 pages, they may experience problems.