A fax number looks like a regular phone number, but it serves a completely different purpose. Here's what a fax number is, how it works, how to format one, and how to get a virtual fax number in minutes.
Frequently Asked Questions
Is a fax number the same as a phone number?
Technically, yes. A fax number uses the same format and the same telephone infrastructure as a regular phone number. The difference is what answers the call — a fax machine or service instead of a person.
How many digits does a fax number have?
In the United States, a fax number has 10 digits (area code + 7-digit local number), following the North American Numbering Plan. International fax numbers vary by country.
Can I use my cell phone number as a fax number?
No. A regular cell number cannot receive fax signals. You need a dedicated fax number connected to a fax machine or an online fax service like [mFax](https://mfax.to) that converts fax signals into PDFs.
How do I get a fax number without a landline?
Sign up for an online fax service. With [mFax](https://mfax.to), you can pick a local or toll-free virtual fax number instantly — no landline, no hardware, no installation.
What happens if you call a fax number from a regular phone?
You'll hear a series of high-pitched beeps and screeches. That's the fax handshake protocol trying to negotiate a connection with another fax device. No voice conversation is possible on a fax line.