Cannot Edit Header Amount of the Invoices Submitted from Supplier Portal

Summary

Cannot modify the Header Amount of the Invoices Submitted from Supplier Portal

Content

The invoice header amount is a read-only field for those Invoices that are submitted from Supplier Portal Page. In the current project , I have a urgent business need that should allow the Payable processors to edit the Invoice Header Amount that are submitted from Supplier Portal. 

The sole purpose to edit the invoice header amount is as follows

1) Pay the Reduced amount by adjusting it against the retainage amount

2) Stop outflow of disbursement in excess to actual amount to be paid to the vendor

Oracle SaaS Financial offering for Payables does not allow the payable processing team to edit the header amount  of the invoices submitted from Supplier Portal. The processing team is cancelling the invoices submitted from Supplier Portal and entering the same details with a invoice number . Due to large volume of Supplier Portal invoices and almost 50% of them requiring change in amount the cancellation and creation of a new invoice with same details has a negative impact on the processing efficiency .