You can send a fax from your computer using an online fax service, your printer's built-in fax feature, or a fax modem if you have a phone line

The easiest route depends on what hardware you have and whether you already have a fax number. If your printer has a fax function and you have a phone line connected to it, you can send a fax directly from your computer without paying anything extra. If you don't have a printer with fax capability, an online fax service like FaxZero, eFax, or HelloFax lets you send faxes through your email or their website — some offer a free tier for a limited number of faxes per month, and paid plans start around $10 to $20 monthly.

A third option is a fax modem card installed in your computer, though this is rare in modern machines and requires a phone line connection. For most people today, an online service is the simplest choice because it requires no hardware and works from any computer with internet access.

Key Takeaways

  • Printers with built-in fax functions can send faxes directly from your computer if they are connected to a phone line.
  • Online fax services let you send faxes through email or a website without owning a fax machine, and many offer a free monthly allowance.
  • You will need the recipient's fax number and, for some services, a cover sheet with your contact information.
  • Sending a fax from your computer typically takes 2 to 5 minutes once you have the recipient's fax number and the document ready.
  • Online fax services store sent and received faxes digitally, so you do not need paper or a physical fax machine.

Sending a fax through your printer's fax feature

If your printer has a fax function — check your printer's manual or the manufacturer's website to confirm — you can send a fax directly from your computer. First, make sure your printer is connected to a phone line. Most printers with fax capability have a phone jack on the back; plug a standard phone cable into it and connect the other end to your wall jack or phone line splitter.

Open the document you want to fax on your computer. Go to File > Print, then select your printer from the list. Look for a button or option that says "Fax" or "Send as Fax" — the exact wording varies by printer brand. Enter the recipient's fax number, add a cover sheet if you want one (most printers offer a template), and click Send. The printer will dial the number and transmit the fax over the phone line. The whole process takes 2 to 5 minutes depending on document length.

One limitation: if someone calls your home phone while a fax is sending, the transmission will stop. If you use your phone line for both calls and faxes, you may want to schedule faxing during times when you are not expecting calls, or ask your phone provider about a dedicated fax line.

Using an online fax service

Online fax services are the most flexible option if you do not have a printer with fax capability or do not want to tie up a phone line. Services like FaxZero, eFax, and HelloFax let you send faxes through a website or email without owning any fax hardware. You create an account, upload or type your document, enter the recipient's fax number, and the service transmits it for you.

FaxZero is free for up to 5 faxes per month in the United States, though you will see an advertisement on your cover sheet. eFax and HelloFax charge monthly subscriptions — typically $10 to $20 per month for plans that include 100 to 500 outgoing faxes. Some services also let you receive faxes at a virtual fax number they assign to you, which arrive as email attachments or PDFs in your account.

To send a fax through an online service, log into your account, click "Send Fax," upload your document (most accept PDF, Word, and image files), enter the recipient's fax number, and submit. The service will add a cover sheet with your name and contact information unless you customize it. Transmission usually happens within minutes, and you will receive a confirmation email with the status.

What documents you need and how to prepare them

Before you send a fax, gather the recipient's fax number — ask them directly or look it up on their business website or letterhead. Have your document ready in digital form: if it is a paper document, scan it to your computer first using a scanner or your phone's camera app. Most fax services accept PDF files, Word documents, and image files like JPG or PNG.

Prepare a cover sheet with your name, phone number, email address, and the date. If you are using a printer's fax function or an online service, you can usually add this information in the service's settings so it appears automatically on every fax you send. If you are sending through an online service, double-check that the recipient's fax number is correct — faxes sent to the wrong number cannot be recalled.

Keep the document file size reasonable. Most fax services have a limit of 10 to 50 MB per fax, which is plenty for typical documents. If you are sending multiple pages, combine them into a single PDF before uploading to avoid sending them as separate faxes.

Understanding fax numbers and transmission timing

A fax number looks like a regular phone number but is connected to a fax machine or service rather than a voice line. When you send a fax, the receiving fax machine or service answers the call, recognizes the fax signal, and stores or prints the document. This happens automatically — the recipient does not have to do anything to receive it.

Faxes typically transmit within a few minutes during business hours. If you send a fax to a number that is busy or offline, the sending service will usually retry automatically a few times over the next hour or two. You will receive a delivery confirmation email telling you whether the fax went through or failed. If it failed, check that you entered the fax number correctly and try again.

Some fax services let you schedule a fax to send at a specific time, which is useful if you want to send something outside business hours or if you are sending to an international number where timing matters.

Troubleshooting common fax problems

If your printer's fax function is not working, start by checking that the phone line is plugged in securely to both the printer and the wall jack. Make sure your printer firmware is up to date by visiting the manufacturer's website and downloading the latest version. Restart your printer and try sending a test fax to a number you know works.

If you are using an online service and a fax is not going through, verify the recipient's fax number by calling them and asking them to confirm it aloud. Check your internet connection to make sure it is stable. If the service shows a failed delivery, try again in a few minutes — the receiving fax machine may have been temporarily offline. If the problem persists, contact the online service's support team or consult your printer's manual for manufacturer support options.

Frequently Asked Questions

Can I send a fax if I don't have a phone line?

Yes. An online fax service does not require a phone line — it sends the fax over the internet instead. Your computer just needs an internet connection. This is the best option if you do not have a landline or do not want to use your phone line for faxing.

What happens if the fax number is wrong?

The fax will be delivered to the wrong recipient or will fail if the number is disconnected. Most services will notify you if delivery failed. Always double-check the fax number before sending, and if possible, call the recipient to confirm it aloud.

Can I send a fax from my phone instead of my computer?

Yes. Most online fax services have mobile apps for iPhone and Android that work the same way as the website version. You can also use your phone's built-in fax feature if it has one, though this is less common on modern phones.

How long does it take to send a fax?

The upload and transmission usually take 2 to 5 minutes depending on document length and file size. You will receive a confirmation email once the fax has been sent, though it may take a few minutes longer to arrive at the receiving end.

Is sending a fax from my computer find?

Online fax services use encryption to protect your documents in transit, similar to how email works. If you are sending sensitive information, choose a service that offers end-to-end encryption or use your printer's fax function over a private phone line instead.