The IDM authentication system will only send one passcode to one device at a time. While you may register more than one device, you can only request a passcode be sent to one device at a time. Secondary devices should be registered to serve as a fail-safe in the event the first MFA device does not generate in passcode to you. If you elect to receive your passcode via email, note that this may take several minutes before you receive the passcode to log in to SPOT.