How does faxing over the Internet work?

A man using a fax machine.
Faxing over the internet is better than using a fax machine. Ghislain & Marie David de Lossy / Getty Images

Internet faxing uses the same principles as facsimile transmission, but it uses a Web interface instead of a fax machine. It can be a flexible, inexpensive option for transmitting documents.

Internet fax services usually assign a fax number to each person who signs up for the service. People can send faxes to this number, and customers can send faxes via e-mail without using a fax machine. Here's how it works.


To send a fax through an Internet fax service:

  • The sender attaches a document to an e-mail message. The document can be a scan of a paper document, or it can be created in a program like Microsoft Word.
  • The sender addresses the message to the recipient's fax number, followed by the name of the faxing service (for example:
  • The service translates the attachment so that a fax machine can read it.
  • The service sends the data across the phone line.
  • The recipient's fax machine decodes the data and prints the fax.

To receive a document from a traditional fax machine through an Internet fax service:

  • The sender dials the fax number that the service has assigned to the recipient.
  • The fax machine translates the data and transmits it over the phone line.
  • The service receives the data, translates it into an image file and sends the image to the recipient's e-mail address.
  • The recipient opens the em-ail message and the attachment and views the file.

To learn more about the Internet and fax machines, follow these links: