In the U.S., the passage of the Telephone Consumer Protection Act in 1991 along with action by individual states reduced the use of junk faxes at that time.
The process of war dialing to determine what phone numbers reach fax machines was also prohibited by the FCC rules under the TCPA.
Additionally, some courts have ruled that unsolicited fax advertisements are common law conversion, independent of any statutory provisions or exemptions.
[1] [2] According to the government legislation on 1 May 1999, it is unlawful to send an individual an unsolicited sales and marketing fax without any prior consent of the customer.
This register is maintained on behalf of OFCOM by the Direct Marketing Association and is branded as the Facsimile Preference Service ("FPS").
[4] Unsolicited faxes are regulated by the Canadian Radio-television and Telecommunications Commission (CRTC) and must follow certain guidelines, but there is no individual right to sue the senders.
Individuals wishing to avoid such faxes may enroll in the CRTC's National Do Not Call List; its effectiveness, however, is a point of controversy.