Autodialer (ATDS, Automatic Telephone Dialing System)

An automatic telephone dialing system, or ATDS, is the legal term the Telephone Consumer Protection Act uses for an autodialer. The statute, 47 U.S.C. 227(a)(1), defines it as equipment with the capacity to store or produce telephone numbers to be called using a random or sequential number generator, and to dial those numbers. Whether a caller used an ATDS matters because the TCPA restricts autodialed calls and texts to cell phones without the owner's prior express consent.

For years, courts disagreed about how broad that definition was. Many consumers argued that any system that automatically dialed from a stored contact list counted. In Facebook, Inc. v. Duguid (2021), the U.S. Supreme Court held that a device qualifies as an autodialer only if it uses a random or sequential number generator to store or produce the numbers it calls. That ruling made many autodialer-based text and call claims harder to bring.

The TCPA is still a strong tool, though. Claims that do not depend on the autodialer definition survived Duguid, including calls using an artificial or prerecorded voice and repeated telemarketing calls to numbers on the National Do Not Call Registry. Each unlawful call or text can carry $500 in statutory damages, and up to $1,500 if the violation was willful or knowing.

If you are getting unwanted calls or texts, save screenshots, voicemails, and call logs with dates and numbers. Our TCPA guide covers what counts as consent, and the robocall lawsuit page tracks how people are bringing these claims now.