Rule 901(b)(6) provides that authentication can occur for a telephone conversation[], by evidence that a call was made to the number assigned at the time by the telephone company to a particular person or business, if (A) in the case of a person, circumstances, including self-identification, show the person answering to be the one called, or (B) in the case of a business, the call was made to a place of business and the conversation related to business reasonably transacted over the telephone. All that is necessary in authenticating a phone call is that the proponent offer 'sufficient authentication to make a prima facie case that would allow the issue of identity to be decided by the jury.' United States v. Register, 496 F.2d 1072, 1077 (5th Cir. 1974), cert. denied, 419 U.S. 1120, 95 S. Ct. 802, 42 L. Ed. 2d 819 (1975). It is not necessary that the person listed as owning the phone number be the actual person answering the phone.
'The calling of a number assigned by the telephone company reasonably supports the assumption that the listing is correct and that the number is the one reached.' Rule 901, advisory committee note example ...