Your first bill will be automatically deducted from the card you signed up with on the date that your free trial ends. That will either be 14 or 30 days from when you signed up, depending on the plan you selected.
You will subsequently be billed for the next period on a rolling month-by-month basis, on the same date each month. However payment may leave your bank account a few days later, depending on your bank and availability of funds.
Unfortunately we cannot arrange payment by invoice. Subscriptions must be paid by direct debit.