Guides

What is a fax number?

Updated November 3, 2026

A fax number is a phone number that answers with a fax machine or an online fax service instead of a person. You only need one to receive faxes: to send a fax, you just need the other side’s number.

Do I need a fax number to send a fax?

No. When you send from sendfaxwell.com/send, Faxwell dials from its own number. Recipients see that number, so if they need to reply, put your phone number or email on a cover page.

Can my mobile number receive a fax?

No. A fax is a phone call where two machines exchange tones; a mobile phone can’t answer that. To receive faxes, you need a number connected to a fax machine or an online fax service, which turns incoming faxes into PDFs you can read on your phone or in email.

How to get a fax number

Faxwell’s numbers come with the iPhone app, coming soon: a number for a week for $2.99 once (handy when you’re waiting on one set of documents), or your own number for $4.99 a month with 100 pages included. Received faxes show up in the app and in your email as a PDF.

What does a fax number look like?

Just like a phone number, with an area code: (503) 555-0147 in the US and Canada. Nothing in the number itself says it’s a fax line, so check with whoever gave it to you.

Questions

Can I receive a fax on my phone?

Not on your mobile number. You need a fax number from an online fax service, which delivers faxes to your phone as PDFs.

Do I need a fax number to send faxes?

No. You only need the recipient’s fax number. Faxwell sends from its own number.

How much is a fax number?

Online fax numbers usually cost a monthly fee. Faxwell’s will be $2.99 once for a week or $4.99 a month, in the iPhone app (coming soon).