1. Go to Finance > Void.
2. Change the Show filter to either Invoice, Receipt or Credit Note as required.
3. Under Action, there will be a Void button to void the existing item.
4. You will be prompted to provide a reason for voiding.
5. Once filling in the reason, click on Submit to void.
Note: Invoices that have been partially or fully paid for cannot be voided unless the receipt for the payments have been voided first.