Reply to a shared reminder list invitation
You receive an email invitation when you’re invited to share a reminder list. You must accept the invitation from this email to have access to the shared reminder list in iCloud Reminders.
Reply to an invitation
Do one of the following:
In the invitation email you receive for the shared reminder list, click Join Reminders.
In iCloud Reminders, select the shared reminder list on the left, then click Join or Decline on the right.
After you accept an invitation, you can view and edit the shared list, and all participants will see the changes you make. Unless you are the owner of the shared list, however, you can’t add or delete participants.