Our customer services is open Monday to Friday 8am - 8pm and Saturdays 8am - 6pm and they can be contacted on 08451 201 453 or online via www.npower.com/web/At_home/customer_service/contact_us/customer_enquiry/index.htm.
As we don't own any of the overhead lines or underground cables (which are usually the prompt for any out of hours calls), we don't have an out of hours service. However, for gas supply emergencies, you can call National Grid on 0800 322 3223.
If it's about your electricity supply, you can contact your local electricity distribution company - the contact number for your area will be on the back of your bill.