Dispenser and refill unit and dispensing methods

A dispenser comprising a base unit with an actuation mechanism for dispensing liquid and a refill unit having an outlet at a lowermost end thereof through which is supplied a liquid from the refill unit to the base unit, the refill unit is insertable into the base unit in an inverted configuration, the refill unit comprising an annular wall projecting into the refill unit and defining an outlet from the refill unit, the annular wall being closable at an innermost end by a valve element biased onto the annular wall, the base unit comprising a hollow spigot and an annular seal surrounding and spaced from the top of the spigot whereby insertion of the refill unit into the base unit causes the spigot to enter the annular wall and to lift the valve element from the annular wall to define a flow path from the refill unit, through at least one cut-out portion formed in the top of the spigot and/or the bottom of the valve element and down the hollow spigot, and the annular seal to seal between the spigot and the annular wall, wherein the base unit also comprises a proximity sensor means, and an inclination sensor means each of which is operable to independently or jointly trigger the actuation mechanism causing the device to operate to deliver one or more doses of liquid from the dispenser.