A method for remotely performing secure change of operational mode of a telecommunications device, the method comprising: establishing a first secure channel between a modem of the telecommunications device and an application executing in an Execution Environment of the telecommunications device; establishing a second secure channel between the application and a remote server; enabling the modem in a limited operational mode; generating a request, by the modem or the application, to verify the validity of a subscriber identity module of the telecommunications device; retrieving, by the modem, module identification information from the subscriber identity module; retrieving verification information, by the application and from the remote server, using the second secure channel, sending the module identification information from the modem to the application using the first secure channel, verifying at the application whether the subscriber identity module is valid using the module identification information and the verification information, and sending the verification result from the application to the modem using the first secure channel, or retrieving verification information, by the application and from the remote server, using the second secure channel, sending the verification information from the application to the modem using the first secure channel and verifying at the modem whether the subscriber identity module is valid using the module identification information and the verification information, or sending the module identification information from the modem to the remote server, verifying at the remote server whether the subscriber identity module is valid using the module identification information and verification information available at the server, sending the verification result from the remote server to the application using the second secure channel, and sending the verification result from the application to the modem using the first secure channel; responsive to a positive verification of the subscriber identity module transitioning the modem from the limited operational mode to an enhanced operational mode.