First, it is important to know that Plannit allows you to delete an invoice only if no payment has been applied to it. If a payment has been applied to the invoice, you must void it first.

To delete an invoice without a payment, select Delete from the Actions menu at the top of the window. The invoice status will be marked as Deleted in Plannit and will become unrecoverable in QuickBooks Online.

To void an invoice while keeping a record, first ensure that you void the payments applied to the invoice, then select Void from the Actions menu at the top of the window. The invoice status will appear as Voided in both Plannit and QuickBooks Online.