UK Privacy and Electronic Communications Regulations 2003 (PECR) Reg.20: Regulation 20: Marketing faxes: consent for individuals, objections and the Fax Preference Service

A person must not transmit or instigate unsolicited direct marketing faxes to an individual subscriber without prior consent to faxes from that sender, to a corporate subscriber that has told the sender not to send them, or to any subscriber whose number has been listed on the fax register kept under regulation 25 for 28 days or more. A listed subscriber may tell a particular sender that it does not for the time being object to that sender's faxes, and may withdraw that notification at any time, after which the sender must stop. Regulation 19 also continues to apply, and a subscriber must not allow its line to be used in breach.