We invoice monthly, from date of order (with the exception of orders placed before 1 Dec 2019 which are usually Invoiced on the 1st day of each month). Generally speaking, we do not process unpaid orders. For example if you placed your order on the 22nd of the month, then you should get an invoice by email on about the 22nd of each month.
Payment for the Invoice is expected on the date the Invoice is generated, for that month’s service (as we are a 'pay in advance' service). Though we do allow a few days grace in making payment.