The definitive guide to online fax (2017)

Last Update: August 9th, 2021

Online fax has quickly become a modern alternative to using a traditional fax machine.

These systems bring fax into the 21st century. Popular features are email faxing (even from Hotmail, Gmail, or Yahoo! Mail); integration with popular programs such as Outlook, Word, and Dropbox; as well as a whole host of features such as signature stamps, automatic resending, HIPAA support, and more.

Fans of online faxing systems point to their convenience as well as the benefits of not having to maintain traditional analog landline telephones, separate fax machines, and costs with long distance and international call costs.


  • An online fax is a web based system (similar to webmail) that is used to send, receive, and store faxes.
  • It is sometimes called “Internet fax,” “web fax,” “VoIP fax,” “email fax,” or an “IP fax,” although those words are relatively interchangeable.
  • Most online fax services have features such sending and receiving faxes from an email address, smartphone, or computer.
  • Power users should consider advanced features such as signature stamps, HIPAA compliance, and contact book integration.

On this page

What is an online fax? a quick history from 1843 to 2017

An online fax is a web-based fax service. It functions like a webmail (Gmail, Hotmail) service for faxes. The system can integrate with email and other software systems.

Internet based faxing is the latest evolution of fax, an invention that has history that predates the telephone, to the time of the U.S. Civil War. Our research has tracked the use of the term “online fax” back to 1990, 2 years after MCI Mail’s “fax dispatch” service was introduced in 1988.

The term “online fax” is often used interchangeably with “internet fax” and a number of other terms. Online fax refers to a hosted system, while Internet fax refers to any system of faxing where faxes travel over the internet, including regular fax machines communicating with the T.38 fax standard.

Compared with a traditional fax machine, an online fax does not require maintenance of equipment, ink/toner, paper, or a landline phone line. It does, however, require a way to access the internet (such as a computer or smartphone).

Compared with a fax server, an online fax is a hosted service where a fax server is locally managed.

Signing up and setting up

Setting up an online fax service is quite easy to do – most of the technology is straightforward.

In most cases, you’ll need an Internet connection, email address, and credit card.

We keep a list of online fax services on our comparison page.

Depending on the service provider, local, toll free, and vanity fax numbers are available. Most providers will allow for porting an existing fax number in, however we advise trailing the service first to ensure that it meets expectations.

There are a lot of different features and functions to consider when looking for an internet fax service, as well the choice can depend on what you’re looking for as an individual.

How to send a fax

Sending a fax can be done through a web page, email, computer, or smartphone.

Regardless of the fax service provider or the format it’s being sent, the steps are roughly the same.

First enter the fax number and receiver information (name, address, phone, etc.).

Second, enter cover page information (usually a quick note about the contents of the fax).

Third, attach any documents to be faxed.

Fourth, send the fax.

Fifth, when the fax is successfully received, you’ll get a notice. If a number of attempts to send it happen and it isn’t sent, you’ll also get a notice.

Sending a fax through a web page

Most fax services have a feature for sending a fax through a web page. These web pages look very much like a webmail program (such as Gmail or Hotmail).

The fields look very much like email. Instead of an email address, there is a field for a fax number. Instead of the email body, there is a field for the cover page.

A file is attached to become part of the fax document (the same way that a webmail client lets you attach a file).

Sending a fax with email

The typical way of sending an email is to send an email to the fax number you want to email @ the provider’s domain.

The subject and body of the email are transferred over to the subject and body of the fax’s cover sheet.

Any attachment(s) to the email becomes the main body of the fax.

Email addresses that you can send from have to be whitelisted, and some providers allow for multiple sending emails.

Any email client such as Outlook and Mac Mail, as well as webmail services (Hotmail, Gmail, or Yahoo! Mail), will work with an online fax system.

Sending a fax with a computer or smartphone

Software and apps let you access a fax provider’s online fax system. Some of this software has advanced features such as special file formats or signature stamps that add to the features available on the web and email interfaces.

Software for Windows is widely available across all versions (XP, Vista, 7, 8, and 10).

MacOS is limited with some providers not offering an Apple version. Linux software support is almost non-existant (although web and email formats still work). Mac & Linux should note that some providers only allow advanced feature setup through a Windows computer.

As for apps, iPhone and Android availability is widespread while Blackberry and Windows Phone support is limited. Users expecting to use apps should take a close look at the software, as some apps only change options and features and do not have full sending capability.

How to receive a fax

When a fax is received to an online fax number, an email notice with an attachment of the fax is sent, and a copy of it is stored with the fax service.

Fax services are always on – there is no need to keep a computer running maintain an internet connection. When a fax arrives, it is automatically received by the service.

Faxes are always stored in PDF, TIFF, or a similar format. When a fax that was, for example, a word document is received, it does not arrive as a word document, rather, it arrives as an image of how the document appeared.

Receiving a fax with email

An email is sent to a designated email address whenever a fax is received. The “from” section is the service provider, the “subject” section is the fax sender’s fax number and other data, and the fax as it was transmitted is attached to the email.

Receive faxes through a web page, computer, or smartphone

Web interfaces, desktop software, or smartphone apps can be logged into for checking faxes.

Just like email, messages can be viewed and forwarded or replied to.

Storing faxes

Faxes that are received are stored with the online fax service for access later on.

The email notice that is sent contains a copy of the fax (typically in PDF or TIFF format). These faxes can be stored with the email service or downloaded and saved.

Popular features

Online fax services have many of the same features as regular fax machines. The extra features bring faxing into an today’s age with features that are more compatible with today’s technology.

Cover sheet customization – A fax services automatically places most of the cover page information (who the fax is from, who it is to, subject line, etc.) into the document. Most include custom cover page logos and layouts.

Integration with a larger suite of phone services – Most online fax providers are also VoIP phone providers, others have a partner that offers VoIP. For some users it helps to mix both voice and fax features into one package.

“Bridge” to an existing fax/printer – Bridging is the ability to use a printer/scanner to directly connect to an online fax service. It aims to replace the automatic printing and faxing of a fax machine.

File attachment support – Some support a wide variety of file formats, others support a smaller group. Support of PDF, TIFF, TXT, and DOC formats are widespread.

Auto re-send – If the fax gets a busy signal, auto-resend keeps trying to send the fax until the service connects (up to a certain number of attempts). It saves the need to sit and wait while the call is redialing.

Software integration – There is some integration with file sharing services such as Dropbox and Google Drive. Integration with Microsoft Office (Outlook, Word, Excel, and more) is possible through directly sending an email.

Scheduled delivery – Scheduled delivery allows for preparing a fax and pressing “send later” to have the fax sent at the designated time. It’s a helpful feature if you’re composing a message late at night and don’t want to ring someone’s fax line until the morning.

Lower long distance rates – As online fax services operate over the internet, there are lower rates for dialing across the country or overseas. Long distance and local rates are often the same.

Lower international rates – International rates with an online fax provider are often far less than they are with the local phone company.

HIPAA compliance – A small handful of fax providers claims that they are compliant with the HIPAA standard. The health care industry (as well as others that need to reach a certain level of information privacy) often use HIPAA as a standard for information privacy.

Logs – Keep track of documents that have been sent and received, as well as the time that the transmissions occurred. Unlike many traditional fax machines, online fax logs do not delete in a power outage.

Contact integration – Sharing fax numbers, names, and addresses between the fax service and an existing address book.

Block junk fax numbers – A block number feature can help keep nuisance faxes out of the office, and cut down on per page costs in the future.

Network infrastructure & connectivity – With an online fax, there is no network infrastructure to maintain. All parts of the system are hosted by the service provider.

International and local support

Support and number availability varies by country.

United States – Online fax is widely available across the lower 48 states, especially in urban areas. Alaska and Hawaii fax number availability is mixed, territory availability is rare.

Canada – Online fax availability in Canada is very good. Canadian local fax numbers are available across all provinces, however territory access is rare. Most Canadian fax systems are compatible across the continent and include calls to the United States as part of their standard packages.

United Kingdom – UK service availability is good. U.K. users should look closely at rates to European countries. Service providers who may be very competitive domestically or within North America may have less competitive rates for international calls.

Australia – Australia has fewer fax service providers than the countries mentioned above. Providers that service Australia have fax numbers available across the country.

Other countries – Many countries are available worldwide including most of the more populous countries of Europe (Germany, France, Spain, Italy) and Asia (India, Japan, Malaysia, the Philippines, Indonesia). Notable exceptions would be Russia and China. These countries may have domestic providers that we do not follow. However, the information in this guide can be used for an online fax service in any country.

Sources and more resources