Don't go near them. I complained about not getting a bill for about 18 months. All my telephone complaints got lost so I started to send them by email. My first two email complaints (according to Npower) didn't count as they didn't give me a complaints number although I got a email reply headed 'Complaint' from them. Then I got a number and was told my bill would take 28 days to generate but my complaint would expire after 10 days. No bill arrived so I started again, and again and again. After five complaints and still not a correct bill I wrote to the Chief Executive. Even then no one read my complaint - still they ignored all my concerns, I even when gave them the readings I had taken regularly over the period (now two years). The executive complaints team re-did the calculation again still using the wrong dates and the wrong meter readings and concluded I didn't have a complaint. For information I did discover that the not charging for electricity if they haven't billed you for over a year only works if you pay when your bill arrives. If you pay by direct debit then they still keep the amount you have paid on account they just don't charge if it would have cost more. Hence my neighbour got £450 knocked off his bill and I got £13. I have given up trying to get Npower to understand the simplest of complaints and I have moved to another supplier, no they weren't much cheaper but at least when I ring them then something happens.