Frequently Asked Question
As far as fiscalization is concerned, you need to send both the item price and total amount after discount, since tax is going to be calculated taking those amounts into account.
You are free to print (display) discount amount to the customer, regardless of it being omitted from the journal returned to you from an SDC.
You are not obliged to strictly follow the journal format, the only requirement is that you display all required invoice elements on your invoice.
So you are free to use the discount in your POS system, but if you send that discount field via invoice request for fiscalization, this information will be ignored by SDC.