You can view this information by going to:
Customer> view all customers> filter by customer> open the customer card
Select “payments and credits” tab
On the customer card there are two balances: “Unpaid Invoices” and “All Unpaid”.
Balance (Unpaid Invoices): This figure is for current orders that have invoice and are outstanding (approved orders with balance owing)
Balance (All Unpaid): This includes the figure above and any other amounts like cancelled orders with no RMAs, unapproved orders, etc.
To resolve these figures, create and close outstanding RMAs and approved orders.
You can filter by balance by going to:
Customer> view all customers> filter by balance
You can export this list as a csv file.