To process / submit invoices to existing orders can be done by following the below steps.
Use the Order Search tools on the dashboard locate your order.
Click the Paper Invoice tab.
Enter the Date and Delivery Note Number and click Save.
If you need to make any adjustments click the Alter button, the follow can be adjusted:
Quantities.
Unit Price.
Net Price.
Tax rate and value.
Products added.
Click Save and Continue to recalculate the invoice as per your changes above and click Save And Compete once all adjustments have been made.
Once the total value matches the suppliers invoice click Confirm Invoice.