Abstract: A method for the operation and control of gas filling from a filling station to a receiver is comprising actively controlling essential filling variables within the receiver such as temperature, pressure, and density of the gas; continuously updating estimates of the filling variables based on filling station side measurements interpreted using physical and thermodynamic relations as to make the variables available even when the receiver is not communicating with the filling station in so-called non-communication fueling; and continuously updating the estimated capacity of the receiver based on station side measurements in a non-communication fueling.