Final invoice indicator set for the purchase order item (delivery costs)

What causes this issue?

You are entering a partial invoice for a purchase order item in which
the final invoice indicator is already set. You want to use the invoice
item to invoice delivery costs. You can only invoice further delivery
cost items for a purchase order item whose final settlement has been
effected if the system issues this message as a warning message.

System Response

If the Customizing settings determine that you get an error message, you
cannot post this invoice.
If you get a warning message, you can post the invoice.

How to fix this error?

In case of an error message, you can park or hold the invoice document.

Error message extract from SAP system. Copyright SAP SE.