If you want to cancel an invoice that has already been approved, you will need to void it. Voiding an invoice will remove the charge from the customer's account and set the invoice status to "Void".
Voiding an Invoice
You can follow the steps below to void an invoice:
Click on "Billing" and then click on "Invoices".
Click on the "View" icon next to the invoice you'd like to void.
Click on "Invoice Options" menu at the top-right of the invoice.
Click on the "Void" option.
Click "OK" in the Confirmation Pop-up to void the invoice.