@whiteowl. Good question. If the meter works correctly it will send readings daily or half hourly and you may be blocked from manual readings. I am not sure. Billing then takes place quarterly and I suppose that is when the DD is recalculated. If the automatic readings stop for some reason then I suppose you can put in manual readings. It will be a new way of managing your account. I send monthly readings as well as you so let us know what happens. Maybe the manual readings are still possible and will still generate monthly bills.