Most of our customers use the P. O. # as a primary source to identify the job and request that before they can talk about open invoices. When I send them a statement of their account they are not able to proceed without it. If that field cannot be transferred to the financial account details list then if there were a blank column which could be used can also be helpful but not preferred because that would need to be manually entered.

I think most companies use a P. O. # and this would help your other customers.