The first step in the process is to consolidate all the open invoices for each customer. Using the sample data presented in Table 9.3, ACL’s Classify command allows the auditor to set a filter to select only the open sales invoices (those with blanks in the Remittance Number field) and to summarize the Invoice Amount field for each record based on the Customer Number. The summarized records are then passed to a new file called Classified Invoices, presented in Table 9.4.