You must be a full owner to delete a sale/invoice.
1 From the Manager Screen, choose “Accounting” and then “Invoices” (You may also locate the invoice on the Real-Time Dashboard if you know the date of the sale).
2 Choose the region and desired dates, (From date → To Date) and then press “Load Invoices.”
3 Locate the invoice you want to edit (You may use the search option) and press “Open Invoice.”
4 Choose the tab “Edit Invoice Data” and confirm your request by pressing “Delete” (You will be required to enter username and password).