Go to: Stock menu > Stock Details > select stock item > Discount tab.
Single discount levels can also be applied using the Standard Discount.
or
in the Discount% field, type the amount of the discount.
The Stock Discounts window
Standard Discount (3 Tier)
Multiple Discounts By Markers
Special Date Discount
To Apply Incentive Discount as Part of End of Month Procedures
To Reverse Discounts on Unpaid Invoices