This invention overcomes the disadvantages of the prior art by providing a method of calculating sorting costs for incoming mail. The foregoing is accomplished by providing a method that can determine the number and types of mailpieces being sorted and associated that number with addressee information. The combination of the number and types of mailpieces being sorted for the addressees can then be used to calculate a charge back amount by using a predetermined cost per mailpiece. Thus, the present invention is directed to, in a general aspect, a method of calculating sorting costs for an incoming mail sorting apparatus having a database of addressees for use in sorting incoming mailpieces comprising the steps of: collecting information about each one of a plurality of mailpieces sorted using the incoming mail sorting apparatus, the information used to determine a type of mailpiece for each one of the plurality of mailpieces; determining the type of mailpiece using the information collected; and associating the information about each one of the plurality of mailpieces sorted using the incoming mail sorting apparatus with addressee information from the database of addressees; and calculating a piece count for each mailpiece for each addressee.