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Fax machine

Fax Number Example and Format – How Long Is a Fax Number?

Fax machine

Before we understand how long a fax number is, let’s first understand what it is.

A fax number is a telephone number that enables you to send or receive documents by fax. It’s more than just a string of digits – it’s a unique identifier that links your landline to your fax machine, creating a bridge for communication.

This seemingly ordinary sequence of numbers can, therefore, enable the sending and receiving of vital documents, transcending geographical barriers.

Now that you know what a fax number is, let’s dive a bit deeper into the question, “How long are fax numbers?” and take a closer look at the fax number format.

Format of a Fax Number

If you’ve seen a U.S. telephone number, then you already have a good idea of what a fax number looks like. That’s because they follow the same format: area code and subscriber number. Example: (123)-456-7890. This format is specifically for local fax numbers.

If you need a fax number for a long-distance transmission, then you’ll need to dial additional digits before the area code and subscriber number. Here’s a long-distance fax number example: (011-44-20-12345678).

How Long Are Fax Numbers?

The length of fax numbers varies from country to country. In the United States, it’s usually 10 digits. Other countries use a different format than the U.S., with some having six- or seven-digit numbers.

Now, in the U.S., fax numbers, much like telephone numbers, typically follow the North American Numbering Plan (NANP). The numbering system is more like a rule book, which dictates the format for both telephone numbers and fax numbers.

At first glance, the 10-digit fax number might seem long, but there’s a structure behind these numbers. They aren’t just randomly arranged digits, and they certainly aren’t random.

The 10-digit number is made up of two parts. We’ve got the 3-digit area code, which typically is the first three digits in a fax number.

The area code is like the home address for the fax number. It represents a specific geographic region. Just as your home address pinpoints where you live in your town or city, the area code helps identify where a phone or fax line is based.

The remaining 7 digits represent the actual fax number, and it’s made up of two parts. The first three digits are reserved for a prefix, which is a code that identifies the service provider (for example, Verizon or AT&T). The second set of four numbers is the actual fax number.

If you’re sending a fax outside the U.S., you’ll need to include the country code, which is a two-digit number that represents where the fax machine is located.

Therefore, the length of the fax number for international fax will be longer than it would be for an American one.

Importance of Knowing Fax Number Format and Length

In today’s world of digital communications, the fax machine may seem like a relic from a bygone era.

However, despite its perceived obsoleteness, the fax machine continues to play a crucial role in many business transactions and official communications.

That’s why understanding the correct fax number format and length remains relevant and essential.

Fax machines, unlike email and messaging apps, can’t correct or suggest the right address if you input it incorrectly.

A fax sent to a wrong number is not just a waste of time and resources; it can potentially lead to a breach of privacy or confidentiality, especially if the document contains sensitive information.

As aforementioned, a fax number follows a specific structure, much like a telephone number. It can include a country code, an area code, and a local number.

Knowing the correct format is essential for ensuring your fax reaches its intended recipient.

For instance, if you’re sending a fax from the US to the UK, you need to use the correct international dialing format. You start with the international access code (011 in the US), then the country code for the UK (44), followed by the local fax number.

Missing or misplacing any of these numbers could result in unsuccessful transmission.

The length of the fax number is equally crucial. If you don’t provide the correct length, the transmission might fail or, worse, end up at the wrong location.

Understanding the correct format and length of a fax number also has practical advantages. You can save time and avoid frustration caused by repeated failed attempts to send a fax.

Moreover, using the correct fax numbers shows that you’re keen and professional. Just like sending an email to the wrong address can reflect poorly on your competence, dispatching a fax to the wrong number can create a similar impression.

Finding Country and Area Codes for a Location

For country codes, the internet is your best friend. Each country has a unique code, usually one to three digits, used universally for international dialing.

Online databases or directories, such as the and provide comprehensive lists of these codes.

Simply type the name of the country you’re interested in, and the site should present you with the corresponding country code. Some smartphone apps also offer this feature.

Finding the area code can be slightly trickier because it varies within the country depending on the region. Again, online resources are quite useful.

Many websites offer searchable databases where you can input a city or region name to find the associated area code.

In the U.S., the North American Numbering Plan Administration (NANPA) offers a comprehensive online area code lookup service. For other countries, try a simple internet search with the name of the city or region and “area code.”

If online research isn’t your preferred method, you could always contact us, and we can help you find the area code.

It’s important to note that while some countries use a specific number format, others follow a mixed-number system where numbers are separated by spaces or dashes.


Understanding the structure of a fax number, including its format and length, is vital for effective communication.

Incorrectly formatted numbers can lead to failed transmissions, privacy breaches, and unprofessional impressions.

While faxing may seem antiquated, it remains relevant in certain industries and regions. Therefore, taking the time to get it right ensures your communications are efficient, accurate, and secure.