In general invoices in Parallels Business Automation - Standard billing are generated automatically, when orders are being paid or in case a subscriber uses resources (e.g., traffic) over the limits stated in his (or her) subscription.
However, it is possible to issue invoices manually, for example, to bill a subscriber for some custom or additional services that cannot be provided in the frame of a subscription upgrade or if there is the need to adjust a customer account balance.
Generally, an invoice issued for a customer account decreases this account balance by an invoice total amount.
However, if it is necessary to increase an account balance, an invoice can be used as an accountable replacement of a credit adjustment. Such an invoice is called a credit invoice.
To add an arbitrary invoice or a credit invoice, open the Billing Director submenu and select Receivable. Click Documents on the Receivable submenu. As the lists of receivables appear on the screen, select the Invoices tab.