Techniques are described herein for authenticating a personal voice assistant using an out-of-band speakable credential. In various embodiments, a user of a mobile application (112) executing on a first client device (104) may be authenticated (302) with a service (110) that executes on server(s) (108) and is configured to interact with personal voice assistant(s). Based on the authenticating, a speakable credential may be provided (304) to the first client device. The providing may trigger the first client device to provide, as output using output device(s) of the first client device, the speakable credential. Data generated in response to an utterance of the speakable credential received at a second client device may be received (306), from a personal voice assistant (106) associated with the second client device (102). The data may be matched (308) to the speakable to authenticate (310) the personal voice assistant with the service.