I find that Express Invoice marks invoices "closed" when the invoice has a zero amount due. Don't confuse this with a paid invoice. I mean when I send a sample of something to a customer and it has a zero amount due. I make an invoice for those so I can keep track of the inventory. It lists these invoices in the open invoices list as "closed."
I don't see any way to get it to list only invoices with balances due in the open invoices list. That would be in a report function. The only options in the invoice list is for All, Recorded, and Draft.
Teri