A checkout apparatus includes a memory that stores first information about one or more commodities registered in a registration process, a first interface configured to acquire an image of a predetermined region where registered commodities are to be placed, and a processor configured to identify commodities in the image acquired via the first interface by object recognition, determine whether each of the identified commodities is in the first information stored in the memory, and if one of the identified commodities is not in the first information, output an error signal.