How to Send a Fax From Your Computer

The three ways to fax from a computer

You can send a fax from your computer in three ways: through an online fax service (the most common route), using fax software if your computer has a fax modem, or through your printer if it has fax capability built in. Most people use an online service because it requires no special hardware and works on any computer with internet access.

Online fax services let you upload a document, type in a fax number, and send it within minutes. The recipient gets the fax on their standard fax machine. You pay a monthly subscription (typically $5 to $20) or a per-fax fee, and the service handles the phone line connection on their end, not yours.

The older method—using fax modem software—requires your computer to have a fax modem card installed and a phone line connected to it. This is rare on modern computers. Printer-based faxing works only if your multifunction printer has fax capability and is connected to a phone line.

Key Takeaways

Online fax services are the fastest option for most people and require only internet access, not a phone line or special hardware.
You will need to create an account with a fax service, upload or compose your document, enter the recipient's fax number, and confirm before sending.
Fax modem software and printer-based faxing are older methods that require a phone line connection and are less common on new computers.
Sending a fax through an online service typically takes 5 to 15 minutes from start to finish, and the recipient receives it on a standard fax machine.

Using an online fax service

Choose a fax service and create an account. Popular options include eFax, Fax.plus, and HelloFax. Most offer a free trial or a low-cost first month so you can test the service before committing. During signup, you will choose a fax number (which becomes your fax identity) and set up payment.

Log in to your account and look for a button labeled "Send Fax" or "New Fax." Upload your document (PDF, Word, image, or scanned paper) or compose a fax cover page directly in the service. Type the recipient's fax number in the format the service requests—usually with the country code and area code, like +1-555-123-4567 for a US number.

Review the document preview to confirm it looks correct, then click "Send." The service will display a confirmation page with a timestamp and reference number. The recipient's fax machine will receive the fax within 5 to 15 minutes. You will receive an email confirmation when the fax is delivered.

Sending a fax through fax modem software

If your computer has a fax modem installed and a phone line connected to it, you can use built-in fax software. On Windows, this is called Windows Fax and Scan (available in Settings under "Apps" or by searching for "Fax"). On Mac, fax capability is built into the print dialog of most applications.

To send a fax on Windows, open the document you want to fax in any process, go to File > Print, and select "Fax" as the printer. Follow the prompts to enter the recipient's fax number and any cover page information. The software will dial the fax modem, send the document, and log the transmission.

On Mac, open the document, go to File > Print, click the dropdown menu that says "PDF," and select "Fax PDF." Enter the fax number and confirm. The system will use your modem to send the fax. This method is slower than online services (it ties up your phone line) and requires the modem and phone line to be active.

Faxing through a multifunction printer

If your printer has fax capability and is connected to a phone line, you can send a fax directly from the printer's control panel or through your computer. Check your printer's manual or the manufacturer's website to confirm it has fax capability—most all-in-one printers do, but not all.

To send a fax from your computer through the printer, open the document, go to File > Print, and select your printer. Look for a "Fax" or "Send Fax" option in the printer settings. Enter the recipient's fax number and confirm. The printer will handle the transmission using its own modem and the phone line connected to it.

Alternatively, use the printer's touchscreen or control panel to send a fax directly. Scan the document using the printer's scanner, then navigate to the Fax menu, enter the fax number, and send. This method does not require your computer to be involved at all.

Common mistakes to avoid

The most common error is entering the fax number in the wrong format. Always include the country code (1 for the US and Canada) and the full area code, even if you are sending to a local number. A fax number should look like +1-555-123-4567, not just 555-123-4567.

Do not assume the fax was received just because the service showed a "sent" confirmation. A "sent" status means the service successfully transmitted the fax to the recipient's fax machine, but it does not may provide the machine was on or the line was clear. If the fax is critical, ask the recipient to confirm they received it.

If you are using fax modem software, do not unplug the phone line or restart your computer while a fax is sending. The transmission will fail and you will have to resend. Online fax services do not have this problem because the service handles the transmission on their servers.

When to use each method

Use an online fax service if you send faxes occasionally or need to fax from multiple locations. It is the most reliable and requires no special hardware. The monthly cost is low, and you can send faxes from any computer or phone with internet access.

Use fax modem software only if you have a fax modem installed and send faxes frequently enough to justify keeping a phone line active. This method is free but slower and ties up your phone line during transmission. It is becoming rare as online services have become cheaper and more convenient.

Use your printer's fax capability if the printer is already connected to a phone line and you send faxes from the same location every time. This works well for a home office or small business, but it requires the printer to stay powered on and the phone line to remain connected.

Frequently Asked Questions

Do I need a phone line to send a fax from my computer?

Not if you use an online fax service—it uses the internet instead. You only need a phone line if you are using fax modem software or your printer's built-in fax feature. Online services are the most common choice for this reason.

How long does it take to send a fax?

Online fax services typically deliver within 5 to 15 minutes. Fax modem software can take 1 to 5 minutes depending on the document size and phone line quality. The recipient's fax machine must be on and have paper loaded, or the fax may sit in the machine's queue.

Can I send a fax to an international number?

Yes, with an online fax service. Include the country code (for example, +44 for the UK or +33 for France) at the start of the number. Fax modem software can also send internationally if your modem supports it, but international calls may incur charges from your phone provider.

What file types can I fax?

Online fax services accept PDF, Word documents, images (JPG, PNG), and scanned documents. Fax modem software works with any document you can print. The service or software converts the file to a fax-compatible format automatically.

What happens if the fax number is wrong?

The fax service will attempt to send to the number you entered. If the number is invalid or disconnected, the service will report a delivery failure and send you an email notification. You can then correct the number and resend. Always double-check the fax number before sending.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.