According to E.ON, an average FixOnline customer will pay £1,035 for their gas and electricity a saving of £123 when compared with the average standard UK tariff.
Jim Macdonald, commercial director of E.ON, said: "We know that everyone is looking for practical ways to save money right now, and FixOnline has been developed to help them do just that."
He added that the firm has already helped its customers save money by offering them one of the lowest gas prices "throughout an exceptionally cold winter".
E.ON's tariff reduction comes into effect today and represents a nine per cent drop in price.
In February, E.ON launched an appeal against the decision by East Riding Council to refuse planning permission for its Tedder Hill windfarm in Roos, Yorkshire.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.