We try to be very lenient on our cancellation policy as long as we do not have to turn people away for your spots, but here is our formal policy... "For reservations of 4 people or less, if you cancel 24 hours or more in advance of the tour there will be no charge. For reservations of 5 people or more, if you cancel 72 hours or more in advance of the tour there will be no charge. Reservations of 4 people or less that are canceled within 24 hours of the tour, reservations of 5 people or more that are canceled within 72 hours of the tour and reservations that no-show will all be charged the full cost of the tour. All cancellations must be in writing and the charged amount is determined upon the date of receipt."