If you think there is a problem with your meter, rather than your bill (which may be based on an estimate) you should contact your supplier. The supplier will be able to perform a simple test to ensure that the meter is working properly. If you are still worried about the meter’s accuracy, you can ask your supplier to have the meter examined by Ofgem’s Meter Examining Service, which is a free test. If you have been overcharged, your supplier will have to repay you the amount overpaid. Be aware though, that an examination may find that you have been undercharged, in which case the supplier has the right to charge for the extra energy that you have used.