@NeilC Thanks for the response.Just one more question, Is the Heating Value figure value derived as a daily, weekly or monthly sum? In other words, what is the period of time that determines the final Heating Value figure that will be used to calculate the amount of gas used in a billing period? BTW, as an AGL customer myself, to which email address can I send a request for the previous heating value data as I mentioned in my initial post? Cheers,Romeo