If the SIM card is removed F-Secure Mobile Security will only function if
- The device has not been factory reset
- The device has a data connection, either through WiFi or a new SIM
- F-Secure Mobile Security is still installed on the device.
If a new SIM card is inserted into the device the same conditions apply.
Note: Information on what will happen to your phone number if your SIM card is changed is available here.