The purpose of the unlock or verification code depends on the camera model.

For FLIR Kxx cameras rated NFPA compliant, and for FLIR GFx cameras rated ATEX certified, the unlock code is required in order to operate the camera.  The certification standards require the camera to be registered so we have the end-user's contact details on file. When you turn on the camera, you will be prompted to enter the four-digit code.

For most handheld cameras (FLIR Exx, T5xx, and similar models), the unlock code is used to remove the registration prompt. The camera will operate normally without entering the unlock code; however, the prompt to register will appear each time the camera is started.  Registration is encouraged since it can extend your warranty for 1 year if registered within a certain time frame.