A method and apparatus for providing in a packet data telecommunication network serving one or more end terminals and/or Mobile Stations (MSs), a method for establishing, managing, modifying, and terminating an End-to-End (E2E) Emergency Service (ES) Chain-of-Trust (CoT) from an Access Serving Network (ASN) and Connectivity Service Network (CSN) to a PSAP, PSAP proxy, or PSAP (i.e. PSTN) gateway that results in the creation of a trust relationship amongst the components in the established ES CoT necessary to allow or validate the granting of any unauthenticated or unprovisioned ES network access and ES operation establishment, modification, and termination requests from amongst the components in an ES CoT to assist a particular terminal/MS or ES network component attempting to establish an ES session between the ES user agent of the terminal/MS and a serving PSAP.