How can I see which invoices are outstanding?

When you click on the Invoicing module in the sidebar menu, the default screen shows you a full list of outstanding invoices - all the invoices that still require payments or part-payments.

On this screen, for each invoice, you can see the date issued, total balance, outstanding balance, and how overdue they are.

If you want to view outstanding invoices for a specific customer, choose to view 'By Customer'. Then select the customer from the drop-down menu.

Within this screen, the outstanding invoices are shown in the top table.

To help you better understand the invoicing module as a whole, please visit the module overview page here.