To prevent such problems, the billing function awaits notification from shipping before it bills. Figure 9.12 shows that upon credit approval, the bill-customer function receives the sales order (invoice copy) from the receive order task. This document is placed in an S.O. pending file until receipt of the shipping notice, which describes the products that were actually shipped to the customer. Upon arrival, the items shipped are reconciled with those ordered and unit prices, taxes, and freight charges are added to the invoice copy of the sales order. The completed sales invoice is the customer’s bill, which formally depicts the charges to the customer. In addition, the billing function performs the following record-keeping-related tasks: