Unwanted faxes - what to do about them
A fax machine is able to send and receive text or images over a telephone line. The Telephone Consumer Protection Act of 1991 (TCPA) and Federal Communications Commission (FCC) rules prohibit sending unsolicited advertisements, also known as "junk faxes," to a fax machines at business offices or residences.
What is unsolicited advertising and when is a fax considered unsolicited?
Unsolicited advertisement is any material advertising commercial property, goods, or services which is transmitted to any person without that persons prior express invitation or permission.
The fact that your fax number is published or distributed doesn't mean others are allowed to send you unsolicited advertisements. However, if you have an "established business relationship" with a person or entity then, consequently you have given your consent to receive faxes from that person or entity.
What is an established relationship?
You have an established business relationship with a person or entity only if you have made an inquiry, application, purchase, or transaction regarding the commercial products or services offered by that person or entity. However, if you want this business or person to stop sending you faxes you can let them know that you don't want to receive anymore advertisement from them (you want to end the established relationship). They would be in violation of the TCPA if they continue to send you unsolicited advertisement.