How to Create a Credit Invoice – Unimarket Helpdesk

Select View Orders from the Orders menu within the Marketplace module.
Using the search filters at the top of the page locate the order.
Open the order by clicking on the order number and the click Invoice Order in the top right corner.
Enter the new credit invoice number and credit invoice date. This credit invoice number must be unique. Duplicate invoice numbers will result in an error. If you need to use the same invoice number, we recommend appending a "C" to the end of the original invoice number, indicating the credit.

Note: Any lines that have a submitted invoice against them will have the checkbox to the left of them deselected.

Select the checkbox to the left of each line you wish to credit.
In the quantity field, enter a NEGATIVE quantity indicating number of items credited.
In the unit price field, enter a POSITIVE dollar amount.

If you are crediting shipping as well enter the shipping amount as a NEGATIVE dollar amount in the shipping box under the invoice lines.
Click Create to submit the invoice.

For more on invoices see Creating Electronic Invoices.