Automatic Invoice On Order
From PhpCOIN Documentation
phpCOIN can automatically create an invoice when a customer places an order, or it can leave invoice creation up to you.
To have phpCOIN automatically create an invoice for every order, set [Admin] -> [Parameters] -> [ordering] -> [invoices] -> [Order Invoice: Auto-Create From Order] to YES.
Within [Admin] -> [Parameters] -> [all] -> [invoices] are other parameters that will control the creation of the invoice, such as the billing cycle, delivery method, status and delivered flag. The default parameters will work for most installations, but you may wish to change the default behavior.
The "Default Billing Cycle" is the billing cycle that will be used for all auto-generated invoices. There can be only one "default billing cycle", so we recommend that you set it to your most commonly used billing cycle and manually change the invoice for those orders that use a different billing cycle.