Pro-Rata Billing
Pro-rata billing is calculated from the date of order till the end of the month.When you place the order, you make the payment for the order the next available invoicing period which starts on the first of the month.
Eg: If an order is placed 5th July 2017 (today) the payment made is for the invoicing period of 5th July, 2017 till 31st July 2017(Pro-Rata) and for 1-8-2017 till 31-8-2017 Invoicing period. So that the recurring invoice will be calculated only for 30 days.