SMS alerts are sent if you do not check-in when you said you would, or, you enter a wrong safety pin, if you manually send an alert or if ICO senses you may have fallen or been involved in a crash.
Share what & when you want
Share what your doing & when you expect to return with anyone you want to have access to your location & profile. After you check-in those permissions expire.
What happens if you lose your data signal?
With data service ICO can monitor your location. Without data, ICO can log your location & once data is restored location information will be uploaded. But ICO will always send SMS alerts if you fail to check-in after your activity expires.
A pin unique to you is used to confirm your identity & need for assistance at each check-in or to cancel an alert . Entering the wrong pin 2x allows you to discreetly send an emergency SMS alert.