These electric companies get an estimated monthly bill from your previous one. This can be extortionate unless you challenge them. I was threatened with bailiffs etc, a moth after taking up with an electric company. After 2 months they said my monthly bill was 850 pounds, a month. I live alone, so I knew it was wrong. I went straight to the top. Typed in CEOs of all electricity companies and the CEOs email came up. I battled for 3 months. Via email. Posting readings etc. Then got a solicitor. Soon changed their mind then. I got a refund of 14.00 pds. Debt disappeared. Then they tried it again by informing my new provider that my monthly dd should be 150 pds. Providers rework together to decide what YOU should pay based on an estimate of last year. When I did not live here. I soon sorted them out too. Result monthly dd of less than 40.00. I advise anyone thinking of taking up with a new provider to go to Trust pilot reviews or similar to find out what existing customers are saying about them. All that glitters is not gold, and customers tell it like it is