A method and apparatus for enabling users of a packet network service, e.g., a VoIP network service, who live in the same household and share a common phone number to have individualized user identifiers to be transmitted along with their call setup messages are disclosed. For example, each user in the household would have a different user identifier which they could retrieve from an endpoint device immediately before dialing the phone number when they want to place a call that would transmit their personalized user identifier in the call setup message.