[SV650rules]

The whole idea of a DD is that energy cost is spread out over the whole year, suppliers are always messing about with DD amount, I have changed suppliers 3 times over DD. If you get through winter to the end of March and and still have more than 1 or 2 DD payments as credit with supplier you are probably paying too much, but that is how your supplier likes it, money in their account not yours. It is probably why they started selling petrol in litres instead of gallons, if price goes up a few pence a litre it will be 4.6x that per gallon, but they hope people will not notice a few pence on a litre. If they charge every month instead of 6 monthly or annually they hope people will not notice, it was only new legislation that came in that made them inform you of price rises and increases in DD, otherwise they never used to bother.