The payment amount for an invoice in a payment run is determined according to the following rules.
If there is no cash discount deduction for the incoming invoice, no cash discount is deducted, and the invoice is included in the payment run on its normal due date (Payment Date field in the invoice).
If a cash discount deduction exists and the "Always deduct cash discount?" checkbox has been selected in the vendor record, the gross cash discount amount is deducted from the invoice amount, and the invoice is inserted into the payment run on the due date of the cash discount deduction (Cash Discount Deduction To field in the invoice).
All other rules are ignored if you manually adjust the payment amount in the Incoming Invoices form during the payment run. In the case of a partial payment, the remaining amount is assigned to the next payment run. An incoming invoice is only marked as paid once the total amount has been transferred.