Adding a credit note In the Module menu, click Financial. In the Menu bar, click Invoices. In the Submenu, click Customer Invoice. Note: Clicking Invoices automatically directs you to the Customer Invoice submenu. Click Add. Select a Customer from the drop-down list. Select Credit Note instead of Invoice from the drop-down menu. Select a Creation Date using the calendar button. Click Create. The credit note appears in the overview. Next, you can edit and complete the credit note in the same way as an invoice. You will need to add revenue lines to the credit note.