Once an invoice is generated, it needs to be Approved, Sent, Processed and Paid in order to transition to its final status - Completed.
Sending an invoice is done by either emailing the customer with a PDF attached or sending the invoice to a printer and mailing the customer directly. In both cases, the default send method is defined on the customer.
Processing an invoice is a step that send the invoice to your Debtors software (like Xero, or BMS Debtors). Once the invoice is sent and a confirmation has been received, the invoice status will transition to Processed.
Once an invoice is fully paid and it’s balance is reduced to $0, the invoice will transition to Completed.