Switchover Billing

I signed up for Bulb on the 6th September when I moved into a new house. I’ve noticed that my Bulb billing starts from the 22nd September. I’ve also just received a bill from another energy company (First Utility) billing me for September, although I don’t have an account with them, and have never dealt with them. Should I pay this bill, and is it possible to confirm who the previous energy supplier was?

This could make some sense. I can see on the industry database that First Utility were previously supplying your new house. The previous occupant of the house is responsible for paying for their energy up until they moved out and you in. If you moved in on the 6th then you will be responsible for paying for the energy from then onwards. I hope this clears things up for you