What is an autodialer (ATDS)?
An autodialer, or automatic telephone dialing system (ATDS), is the TCPA's term for equipment that can store or produce numbers using a random or sequential number generator and dial them. Autodialed calls to mobile phones, and to certain other lines such as emergency and hospital lines, need the called party's prior express consent, and autodialed telemarketing calls to those numbers need prior express written consent.
In 2021 the Supreme Court read the definition narrowly in Facebook v. Duguid: a system only counts if it uses a random or sequential number generator to store or produce the numbers. Many modern dialers that call from a list fall outside that definition. That does not end the analysis. The consent rules for artificial or prerecorded voices apply regardless of how the number was dialed, and the FCC ruled in 2024 that AI-generated voices are artificial voices. Several state laws also use their own, broader definitions. Residential landlines are treated differently under federal law: the autodialer consent rule does not cover them, but a call to a landline that uses an artificial or prerecorded voice still needs consent.
In practice, outbound teams that use AI voice agents treat every call as needing documented consent and keep records of it.