Available in Sage 50 Premium Accounting and higher.
The billing amount is equal to the Quantity multiplied by the Unit Price.
Tip: Although you can change the value in the Billing Amount field, Sage 50 will change the value in the Quantity field automatically to compensate for the change, while the Unit Price will remain the same. If you want to change the amount that you bill the customer for, you can write-up the amount when you apply the ticket to a sales invoice.