Understanding Invoice Amount Revisions for Non-T and M Contract Billing Lines
You can add an amount to an existing invoice that already contains pay items. In this case, you can:
Add the non-T and M billing amount.
Revise a related retainage amount.
Revise a related fee line amount.
You can update only certain fields, depending on the pricing type of the contract billing line. You cannot update any field for direct and rated draw pricing types. After you enter the information, the system updates the Invoice Summary Work File table (F4822).