Add a Required Invoice Review before delivery

Two times so far, I intended on altering the invoice to add charges and failed to do so. My fault? YES but to prevent it, especially for those photographing, Editing, QA'ing multiple shots a day it would be a great feature to add after hitting Deliver, to have a pop-up reminding (Yes/No) to alter the invoice before delivery so we don't accidentally leave money on the table like I have twice so far.