How to set up your printer's fax

Fax needs an analog phone line. If you have DSL broadband on the same line, fit a DSL filter between the wall jack and the printer, or faxes will fail. If your phone service comes through a cable or fiber box or a VoIP adapter, plug into that box's phone port; faxing works on many of these lines but can be less reliable. Office phone systems often need a dedicated analog port for a fax.

Plug one end of the phone cord into the wall jack, or the DSL filter, and the other into the printer port marked LINE, often shown with a wall-jack icon or the number 1. Use the cord that came with the printer if there is one, because some ordinary phone cords aren't wired the way the printer expects. In some countries you also need a plug adapter for the wall socket.

To use one line for voice calls and faxes, plug your phone or answering machine into the printer port marked EXT, which may have a small plug or cover to remove first. If you have both, connect the answering machine to the EXT port and the phone to the answering machine. Connecting through the EXT port, rather than a splitter at the wall, is the arrangement most printer manuals describe and usually works best.

Open the printer's setup or fax setup menu and set the date, time and, if asked, the country or region. The printer stamps the date and time on every fax you send and in its fax reports, and the country setting adjusts the fax to suit your local phone network.

The fax header is the line printed at the top of every page you send, showing your name or business name and your fax number. Enter both in the fax setup menu, or on the printer's built-in web page, which is easier to type on. In some countries, including the United States, the law requires faxes to identify the sender and the sending number, so don't leave it blank.

Use automatic answer (sometimes called Fax only or Auto answer) if the line is used only for fax, or if an answering machine on the EXT port takes your voice calls. Choose manual answer if you mostly take voice calls on that line and want to start each fax yourself, usually by pressing Start or Receive when you hear fax tones. Some printers also offer a fax/phone mode that answers and works out whether the call is a fax or a voice call; names vary by model.

On a dedicated fax line, set the printer to answer after one or two rings. When an answering machine shares the line, set the machine to answer first, after fewer rings, and the printer to answer after more; the printer then listens on the line and takes over if it hears fax tones. Faxes that go to a voicemail service can't be picked up by the printer, so with voicemail use manual answer, or, if your phone service offers a distinctive ring number, assign it to fax and turn on the printer's distinctive ring setting.

If you need to dial a prefix such as 9 to reach an outside line, add it as a dial prefix in the fax settings. Leave tone dialing on unless your line is unusually old. If faxes often fail partway through, lower the fax speed in the advanced fax settings; on some lines, changing the error correction mode (ECM) setting also helps.

Many printers have a fax test or line check in the fax setup or tools menu that checks the cord, port and dial tone, then prints a report; fix anything it flags. Next, send a one-page fax to a fax number you know works and ask the recipient to confirm it arrived and is readable. Turn on a send confirmation report if you want proof of each fax.