If a Disc % was entered, this field defaults an amount based on the percentage specified and the invoice line’s gross amount (less retainage, if any). Accept the default, or enter the discount amount. If you change the default amount, the discount percentage is recalculated.
Discounts are not calculated on Misc amounts. Also, if you enter a discount amount here, a discount date must be entered in the header. If a discount date is not entered, a warning displays when you validate the batch (AP Batch Process).
If using tax discounts (flag in AP Company Parameters), the discount will be taken by subtracting this amount from the invoice's gross amount to get the tax basis.