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Save the offending faxes, use the opt-out notice printed on each one, and complain to the FCC if they keep coming. In the US, sending unsolicited ad faxes is broadly illegal under the Telephone Consumer Protection Act (TCPA), so you have more power here than with spam email. There is no national do-not-fax registry, so the process runs fax by fax.
A junk fax is an unsolicited advertisement sent to a fax machine or fax number. The legal definition is wider than most people expect: it covers ads for products, services, and events, including "free" offers that exist to sell you something later. What it does not cover is informational faxes: appointment reminders, service updates, or faxes from someone you have an existing business relationship with. Before you fight a fax, sort it into ad versus informational, because the law treats them very differently.
| Step | What to do |
|---|---|
| 1. Save it | Keep the fax with the transmission header showing the sender's number and date; this is your evidence |
| 2. Find the opt-out notice | US law requires every fax ad to include opt-out instructions with a phone number, fax number, or address you can use |
| 3. Opt out in writing | Send a written do-not-fax request by fax or mail naming your fax number; keep a copy and the confirmation |
| 4. Log everything | Note the date, sender number, and ad content of each fax; a log turns a nuisance into a case |
| 5. Complain to the FCC | File a complaint at the FCC's consumer complaint site if faxes continue after your opt-out |
Yes, once they receive it. The TCPA prohibits sending unsolicited ad faxes without the recipient's prior express permission, and senders must honor opt-out requests. The catch: the permission exception. If you gave a business your fax number (say, on a form or in a contract), they may argue they have an established relationship. That defense has limits, though: faxes still must carry the opt-out notice, and they must stop once you opt out. If the same sender faxes you after your written opt-out, the law is on your side.
The TCPA lets recipients sue for statutory damages per unsolicited fax, which is why junk-fax litigation became a small industry. Courts have awarded damages in class actions that made the practice expensive for repeat offenders. In practice, most people never sue: the opt-out and FCC complaint route resolves the common cases, and the repeat offenders who ignore both tend to disappear under regulatory pressure. If you are getting dozens of identical faxes from one operation, a consumer-protection attorney may take the case on contingency, but that is the exception, not the plan.
Give your fax number out sparingly. The biggest source of junk faxes is fax numbers scraped from business directories, registrations, and public filings, so use a separate number for public listings if you fax regularly. If you still own a physical fax machine, some models let you block specific sender numbers, though spammers rotate numbers freely. Online fax services often have spam filtering built in, and many let you block or report junk senders in one click. If your number is drowning in spam, changing the number is the nuclear option: cheap with an online service, annoying with a landline.
Canada's approach is similar but runs through different rules. Unsolicited fax ads can violate telemarketing and anti-spam rules depending on the content and sender, and the CRTC handles complaints about unsolicited commercial communications. The practical steps are the same: save the fax, use any opt-out mechanism, send a written request, and complain to the regulator. Canadian residents can also check with the CRTC's current complaint process for unsolicited communications.
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