This article will show you how to use a discount when processing a sale on the Purchase screen.
When checking a client out, you can click the + symbol to apply a Discount to the sale.
After clicking the plus button, you'll be able to choose the default Percentage or Amount discount types, or you can choose any custom discounts that you have created.
Creating a New Custom Discount
Click here for a step-by-step guide on how to create a new custom discount.