The below steps will show you how to do the setup for allowing discounts at the payment stage after the invoice/open item was created.
Step 1 - Confirm that the Accounting code setup is correct
1a) Navigate to Setup> Financials> Accounting codes
1b) Select the “Payment” type
i) Enter the GL account to be affecting when there is a discount received on a payment receipt i.e., Profit line
ii) Enter the GL account to be affected when there is a discount granted on a payment issue i.e., Loss line
Step 2 - Then when capturing the payment, select the invoice and enter the discounted amount on the first line
2a) On the second line, select Attribute [ZASDT] and enter the discount amount
i) You can select a VAT code where applicable
Step 3 - The Journal is created
For more information on Sage X3 contact us on email@example.com or by phone on +27 12 880 0258.