The U.S. Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer or other electronic device to send any message via a telephone fax machine unless such message clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent and an identification of the business or other entity, or other individual sending the message and the telephone number of the sending machine or such business, other entity, or individual.
While the application of the TCPA to computer fax modems is being considered by the FCC, users are strongly advised to follow the procedures below to ensure that their faxes are properly identified.
Note also that FCC rules ban the transmission of unsolicited advertisements to telephone facsimile machines. An "unsolicited advertisement" is defined as a transmission advertising the commercial availability or quality of property, goods or services without the prior express invitation or permission of the person or entity receiving the transmission.
Unsolicited advertisements may not be transmitted by any device to a telephone facsimile machine unless the person receiving the facsimile has given prior express invitation or permission to receive it. If the sender and the recipient have an established business relationship, an invitation or permission to receive unsolicited facsimile advertisements is presumed to exist. However, the recipient may end an established business relationship by requesting that no further unsolicited advertisements be sent, thus revoking any invitation or permission to receive further transmissions.