Creating and using items that calculate

QuickBooks has four item types that perform calculations on the amounts of a sales form. If you want to perform any of these calculations, you must have an item for each calculation you need.

Type Use when calculating
Subtotal A subtotal. You must use a subtotal item before calculating a discount or a charge that covers several items.
Discount An amount to be subtracted from the total. If you are applying the discount to more than one item, you must first use a subtotal item and then apply the discount to the subtotal.
Payment Partial payment you receive at the time you write an invoice. A payment item reduces the amount owed on an invoice.
Sales tax The tax that QuickBooks calculates in the Tax field on sales forms. (QuickBooks also uses this field to calculate non-taxable sales for the sales tax liability report.)