Mentioning your intentions by sending this form to a trusted contact is one of the most important things that you can do before heading out. This form includes all key information Search and Rescue will need if you don't return home when expected.
What to do if you are a nominated, trusted contact
If a person or group that you are a trusted contact for doesn't return when expected, then you need to:
Try to contact them, and then other members of the group (if any), as well as friends and family members who may know of their whereabouts.
Wait one more hour if you can't get hold of anyone who knows where they are.
Try contacting them again after one hour.
If you still haven't heard form anyone after this time, phone 111 and ask for Police.
You can fill out the form here.