NPower are a failing business from a customer service point of view. My elderly relative received a communication from them to say she was over £400 in credit, however when she gave her meter reading the credit amount disappeared. When I spoke to them on her behalf, I wasn't satisfied with the explanation for the billing and credit amounts. The person on the end of the phone was nice enough but there seems to be a marketing / business strategy problem in communicating the 6 month billing account that my mother in law was on. In my opinion, the account was not fair, they communicated a huge credit at the beginning of the period which was misleading especially for pensioners on low income. Poor customer service and poor marketing and communication. Don't waste your time, there are plenty of better suppliers to chose from. In my relative's words "They are without doubt the worst company ever to deal with!"