Currently the invoice content is automatically generated from the sale order and it is not possible to make any changes to this without undoing the authorized order and making changes in that. It basically makes the invoice tab redundant as far as I can tell as it is just the same thing as the order tab.
Why can't it be like it is with purchase where the order tab and invoice tabs are 2 separate things?
problem we are having is after the sales team has entered the customer
order if the accounts team wants to make any changes to the final
invoice like giving extra discount, or if there are changes due to
picking (more/less quantity than order for whatever reason) they have to
go back and change the order to draft, but then they are not to have
the user permission to create/authorize orders and have to rely on sales
team to authorize the order all over again.