Open any QuickBooks window, dialog box, or form, and you’re bound to bump into at least one drop-down list. These lists make it easy to fill in transactions and forms. Creating an invoice? If you pick the customer and job from the Customer:Job drop-down list, QuickBooks fills in the customer’s address, payment terms, and other fields for you. Selecting payment terms from the Terms List tells the program how to calculate an invoice’s due date. If you choose an entry in the Price Level List, QuickBooks calculates the discount or markup you extend to your customers for the goods they buy. Even the products and services you sell to customers come from the Item List.