Npower are crooks and charlatans. They sign you up to a reasonably priced tariff and after a month or so they more than double it and rip you off mercilessly. I think this is their business model. Get new customers,rip then off until they have enough and leave,and repeat. I advise everyone to stay away. I live in a one bedroom flat and my monthly cost went from £40 to £100 a month. Considering a never use the electric heating and use minimal appliances it's blatant theft. For contrast OVO energy now charge me £45 a month and I'm not overusing energy of going above my tariff. Do yourself a favor. AVOID. AVOID. AVOID.