Confirmation number at the end of the call. Confirmation numbers are codes that hotels use to validate and track guests reservations. When taking guests reservations, the hotel reservationist should provide the guest with a confirmation number near the conclusion of the call after the terms of the bookings have been set. Often, hotels will also send an e-mail to guests that contains their confirmation numbers. If guests need to make changes to their reservations, they provide their confirmation numbers to the reservationists, which help them access and change the guests information quickly. Reservationists do not provide guests with daily transaction codes, policy reference numbers, or arrival identification codes.