The invention provides a method performed by a home public land mobile network, PLMN, of controlling access of a user equipment, UE, device to a non-home PLMN when the UE device has an access to a non-trusted network and thereby a connection with the home PLMN via an interworking function entity, the method comprising in the event of the UE device requesting an attachment to the non-home PLMN, making in the home PLMN a decision as to whether control of the UE device should be handed over to the non-home PLMN; and communicating the decision to the non-home PLMN.