A method and apparatus are disclosed for a network node which processes a call request from an enterprise user's mobile device to initiate origination of an outgoing cellular call to a called party by making an external call to the mobile device which does not have a country code encoded in its SIM card by transforming an International Mobile Subscriber Identity (IMSI) value from the SIM card into a country code value, and then using the country code value to construct a dialing sequence for calling the mobile device.