Yes, you can fax from your computer to a traditional fax machine

You can send a fax directly from your computer to any fax machine without owning a physical fax device. Your computer connects to a fax service—either through your internet connection, your phone line, or software installed on your machine—and that service handles the transmission to the receiving fax machine on the other end. The process is straightforward once you choose which method works for your setup.

The main routes are online fax services (the easiest for most people), fax software that uses your modem, or your printer's built-in fax feature if it has one. Each has different requirements and costs, so the right choice depends on how often you fax and what equipment you already own.

Key Takeaways

  • Online fax services like FaxZero, HelloFax, and Fax.plus let you send faxes through a web browser or email without installing anything.
  • Fax modems and fax software work through your phone line if your computer has a modem, but most modern computers no longer include one.
  • All-in-one printers with fax capability can send faxes if they are connected to a phone line and your computer has the right drivers installed.
  • Online services charge per fax or per month depending on volume, while modem-based faxing requires only a phone line connection.
  • The receiving fax machine sees no difference between a fax sent from your computer and one sent from a traditional fax machine.

Online fax services: the easiest route for most people

Online fax services are the most common way to fax from a computer because they require no hardware beyond what you already have. You upload a document (PDF, Word, image, or scanned file), enter the fax number, and the service transmits it to the receiving fax machine. Services like FaxZero, HelloFax, Fax.plus, and eFax all work this way, though they differ in cost and features.

FaxZero is free for up to five faxes per month within the United States and Canada, with a small fee per page if you exceed that. HelloFax and Fax.plus charge monthly subscriptions (usually $10 to $30 per month) for unlimited faxing, or you can pay per fax if you send only occasionally. eFax is a longer-established service that charges monthly and includes a dedicated fax number if you want to receive faxes as well.

The main limitation of free or low-cost services is that they may add a cover page with advertising, or they may not support certain file types. Check the service's requirements before you upload a large or sensitive document. Most services also have a maximum file size—typically 10 to 25 megabytes—so very large scans may need to be split into multiple faxes.

Fax modems and fax software: using your phone line

If your computer has a fax modem (a hardware device that connects to your phone line), you can use fax software to send faxes without relying on an online service. Windows includes built-in fax capability through the Windows Fax and Scan app, and Mac users can use third-party software like eFax or Pamfax. The modem dials the receiving fax machine's number and transmits the document directly.

The catch is that most computers sold in the last 10 years do not include a modem. If your computer is older or you have an external USB modem, this route is free beyond your regular phone line charges. If you do not have a modem, buying one now is usually not worth it—online fax services are cheaper and simpler.

To check whether your Windows computer has fax capability, open Settings, go to Apps, then Apps and Features, and search for "fax". If Windows Fax and Scan appears, your computer has the software ready. You will still need a modem connected to a phone line to actually send faxes. On Mac, fax capability varies by model and macOS version, so check Apple's support pages for your specific machine.

All-in-one printers with fax features

Many modern all-in-one printers (also called multifunction printers) include a fax feature. If your printer is connected to a phone line and your computer has the printer drivers installed, you can often send a fax through the printer's software or directly from your computer's print menu. The printer then uses its own modem to dial and transmit the fax.

To use this method, your printer must be plugged into a phone jack, not just a USB or network connection. Check your printer's manual or the manufacturer's website to confirm it has fax capability and to read the latest drivers. Some printers require you to open the printer's control panel and enter the fax number there, while others let you send faxes directly from your computer through a software interface.

This option works well if you already own a compatible printer and have a phone line available. If you do not have a phone line at your desk or your printer lacks fax capability, an online service is simpler than upgrading your hardware.

What information you need to send a fax

Before you send a fax, gather the recipient's fax number and make sure your document is in a format the service accepts. Most services accept PDF, JPEG, PNG, TIFF, and Microsoft Word files. If you have a paper document, you will need to scan it first using a scanner or a smartphone scanning app.

Some services ask for your name and phone number so the receiving fax machine can print a cover sheet. A cover sheet is a standard first page that identifies who sent the fax and includes a brief message if you want one. Online services usually generate this automatically, though you can often customize it or skip it entirely.

If you are sending to a business, double-check the fax number before you submit—fax numbers are straightforward to mistype, and a misdirected fax may reach someone else's machine. Many services let you preview the document before sending, so use that feature to catch any errors.

Costs and when to choose each method

Online fax services cost nothing to a few dollars per fax if you send occasionally, or $10 to $30 per month if you send regularly. Modem-based faxing costs only your phone line charges (usually included in your home or business phone plan). Printer-based faxing also costs only your phone line.

Choose an online service if you send faxes infrequently, do not have a phone line at your desk, or do not want to deal with hardware. Choose a modem or printer if you send faxes regularly and already have a phone line connected. If you need to receive faxes as well as send them, online services with a dedicated fax number (like eFax) are usually more convenient than managing a modem or printer.

Frequently Asked Questions

Does the fax machine on the other end know it came from a computer?

No. The receiving fax machine sees only the document and the cover sheet, just as it would from any other fax machine. There is no way for the recipient to tell whether you sent the fax from a computer, a traditional fax machine, or a printer.

What if the fax number is busy or does not answer?

Online fax services automatically retry the number several times over a few hours. If the fax still does not go through, the service notifies you and usually lets you try again at no extra charge. Modem-based faxing behaves the same way—the software will retry and alert you if it fails.

Can I fax to an international number?

Most online fax services support international faxing, but it usually costs more per page than domestic faxes. Check the service's pricing page to see which countries are supported and what the rates are. Modem-based faxing can also send internationally if your phone service supports international dialing.

Do I need a fax number to send a fax?

No. You only need the recipient's fax number. Some services will assign you a fax number if you want to receive faxes, but sending does not require one. Your name and phone number on the cover sheet help the recipient know who sent it, but they are optional on most services.

What happens if my document is too large to fax?

Online services have file size limits, usually 10 to 25 megabytes. If your document exceeds that, split it into smaller files and send multiple faxes, or compress the file using your computer's built-in tools. For very large documents, ask the recipient whether they can receive the file by email instead.