You can determine which orders have been paid via the Payments tab in the Marketplace Portal. Once there, you can download the details in a PDF or CSV format for each invoice.
Alternatively, you can identify whether an order has been paid or not via the marketplace portal. To do this locate the order within the portal and view the 'Order Details' column. The Seller Payment Status will show as "Paid" for orders that have been paid and the applicable invoice number and payment date will be listed.