If you need to cancel an invoice sent to your customer for any reason, you must send a credit note.
What is a credit note?
A credit note is the opposite of an invoice and means that the seller owes money to the buyer. It is necessary when a billed product or service needs to be refunded to the customer. The amount on the credit note is deducted from the amount on the original invoice and can be refunded as a cash payment, bank transfer, credit voucher, or by adjusting the balance on an open account.
You are not able to create a credit note yourself in our system.
Therefore, you need to contact our support to cancel your invoice. They will help you cancel it in our systems and send a credit note to your customer.