Probably.

In 1991, Congress enacted the Telephone Consumer Protection Act. Part of this act made it unlawful to send unsolicited advertisements to a fax machine without the recipient’s prior permission. However, in 2005 the Junk Fax Prevention Act was signed into law. That act amended the TCPA to allow faxes to be sent to recipients, without prior consent, if there is an established business relationship.

An established business relationship is a prior or existing relationship formed by a voluntary two-way communication between the sender and the recipient. However, the JFPA also allows senders to fax those whose numbers they received from “a directory, advertisement, or site on the Internet to which the recipient voluntarily agreed to make available its facsimile number for public distribution.” There is no time limit on this exception. So, if a fax number appeared on such a list 10 years ago and a sender obtains that list, they can send faxes to that number without being penalized. If a fax owner never put his or her fax number on any type of list that could be available to the public and has no business relationship with a sender, he or she can sue the sender of the unsolicited fax.

However, some states may have laws regulating faxes sent within their states that are more stringent than the JFPA.