A method and apparatus for attaching a wireless device to a foreign wireless domain of a 3GPP communication system using an alternative authentication mechanism, wherein wireless device performs the method, which includes: sending a first attach request message to an infrastructure device in the foreign wireless domain; receiving an attach reject message from the infrastructure device upon an unsuccessful attempt to obtain authentication credentials for the wireless device from a home wireless domain of the wireless device using a standard 3GPP authentication mechanism; responsive to the attach reject message sending a second attach request message to the infrastructure device, wherein the second attach request message indicates an alternative authentication mechanism to the standard 3GPP authentication mechanism; and receiving an attach accept message from the infrastructure device when the wireless device is successfully authenticated using the alternative authentication mechanism.