A method for selecting a Public Land Mobile Network, PLMN, at a user equipment, UE, the method comprising: determining (210, 310) that a first trigger condition has been met, wherein the first trigger condition is at least one of the UE changing PLMN, a timer expiring, a PLMN of the UE becoming unavailable to the UE, and the UE receiving an indication to perform migration to a partner Mission Critical, MC, system; transmitting (220, 320) to an identity management server a token request, the token request comprising: an indication that the UE needs PLMN identifiers to access a partner MC system, location information for the UE, and an indication that the first trigger condition has been met; receiving (230, 330), from the identity management server, in an ID token, a list of PLMN identifiers, wherein each PLMN identifier in the list of PLMN identifiers corresponds to a PLMN that allows the UE to migrate to a new MC system based on the location of the UE; attempting to register (250, 351) the UE with a network using at least one PLMN identifier from the list of PLMN identifiers; and if the attempt to register (250, 351) with the network is successful, performing (270, 380) a Session Initiation Protocol, SIP, registration to an Internet Protocol, IP, Multimedia Sub-system, IMS, associated to the PLMN identifier and migrating (270, 380) to the new MC system. determining (210, 310) that a first trigger condition has been met, wherein the first trigger condition is at least one of the UE changing PLMN, a timer expiring, a PLMN of the UE becoming unavailable to the UE, and the UE receiving an indication to perform migration to a partner Mission Critical, MC, system; transmitting (220, 320) to an identity management server a token request, the token request comprising: an indication that the UE needs PLMN identifiers to access a partner MC system, location information for the UE, and an indication that the first trigger condition has been met; receiving (230, 330), from the identity management server, in an ID token, a list of PLMN identifiers, wherein each PLMN identifier in the list of PLMN identifiers corresponds to a PLMN that allows the UE to migrate to a new MC system based on the location of the UE; attempting to register (250, 351) the UE with a network using at least one PLMN identifier from the list of PLMN identifiers; and if the attempt to register (250, 351) with the network is successful, performing (270, 380) a Session Initiation Protocol, SIP, registration to an Internet Protocol, IP, Multimedia Sub-system, IMS, associated to the PLMN identifier and migrating (270, 380) to the new MC system. an indication that the UE needs PLMN identifiers to access a partner MC system, location information for the UE, and an indication that the first trigger condition has been met; receiving (230, 330), from the identity management server, in an ID token, a list of PLMN identifiers, wherein each PLMN identifier in the list of PLMN identifiers corresponds to a PLMN that allows the UE to migrate to a new MC system based on the location of the UE; attempting to register (250, 351) the UE with a network using at least one PLMN identifier from the list of PLMN identifiers; and if the attempt to register (250, 351) with the network is successful, performing (270, 380) a Session Initiation Protocol, SIP, registration to an Internet Protocol, IP, Multimedia Sub-system, IMS, associated to the PLMN identifier and migrating (270, 380) to the new MC system.