I’ve just received a massive bill from Eon over £300 is that right when I’m also paying yourselves.

I’m guessing it’s your ‘final bill’ from Eon and that the ‘supply address’ matches yours? Do the meter serial numbers match on E.On’s and Bulb’s bills? [If all that is correct, then it’s for the correct property and somebody hasn’t switched their power to E.On with your billing address somehow].

If it is the final bill, does E.On’s ‘closing read’ number match the ‘opening read’ number on Bulb? If so, that bill is for the energy you used whilst you were still with E.On (if you hadn’t been providing them with regular meter readings, they may have been underestimating your usage and, with a switch, they may have received a proper meter reading and found you they have been underbilling/charging you for quite a while).

If there are any ‘Contract Exit fees’ on the bill though (say you were in an 18 month contract with them, but left after 12 months and they charged you £60 per fuel), then Bulb will pay those exit fees https://help.bulb.co.uk/hc/en-us/articles/115001227591-What-about-exit-fees-from-my-current-supplier- .

Other help documents that may be of use:

Hi @maxjames17 Its very much dependent on what your account situation with them was. If you had a large debt on your account the final bill will be very large. Looking at your account it looks like we’ve sent over everything and the reads we are using to open your account look correct. I would get in contact with EON to see why they might have given you such a final high bill.