A Certificate of Insurance, or COI, is a million-dollar liability insurance from a vendor provided for certain lodging and activities.
High adventure activities require a COI as part of the approval process.
Lodging at a hotel chain, campground, or for accommodations booked via VRBO or Airbnb will not require a COI. However, if you are planning on staying somewhere reserved via another booking site, an independent vendor (such as a bed-and-breakfast), or at a personal cabin, home, .etc, you will need to provide a COI for lodging as part of the approval process.