There are provided systems and methods for automatic authentication for a user with a service provider during a voice data connection to a merchant. A user may place a voice call to an entity, for example, through a plain old telephone service (POTS) or through voice over IP. The voice call may be detected by a service provider, which may determine whether the entity receiving the voice call requires authentication of the user during the voice call. The service provider may further determine whether the entity requires authentication of the user for use of an account with the service provider. The service provider may communicate information used to authenticate the user to the entity during the voice call. Additionally, the service provider may generate an authentication mechanism for the payment account, which may be used to authenticate use of the payment account by the user during the voice call.