See this page for general information about creating documents.
The Parts Tab
Add parts to the Invoice in the "Parts" tab.
Formsets
Formsets are used to add both parts and price adjustments to an invoice.
See the "Formsets" portion of this page for details on how to work with formsets.
The Subtotal
A subtotal is displayed in the form, and this number gets updated when you add parts to the Invoice using the formset, or when you update either the Qty or Price of an included part. A part will only count towards the displayed subtotal if both its "Price" and "Qty" fields are filled out.
Price Adjustments
Non-part line items ( such as discounts or small nudges to bring the price to a round number ) can be added to an Invoice via the Price Adjustments formset. The dollar amount of the adjustment will be added to the Invoice's total, so if you want to apply a discount, the "addition" field must be negative.
If you'd like the adjustment to be a percentage of the subtotal, you can click on the "%" button on an adjustment form. Enter the desired percentage and the "addition" field will be automatically filled with the appropriate amount. if the subtotal changes after the percentage was calculated, the percentage will no longer be accurate. You must calculate the percentage again, once the subtotal has been "finalized".
For your convenience, if you include the word "discount" in the "adjustment name" field, the "addition" field will automatically receive a negative sign, resulting in a reduction of the grand total.