Which? Legal member Ian Walker came to us for advice after his energy firm tried to recalculate his bill and charge him extra. Has your energy supplier ever changed your bill?
Ian switched gas and electricity supplier from British Gas to First Utility in October 2012 and had a new gas meter fitted by National Grid in June 2013.
First Utility was told and given the old and new meter readings. But when Ian checked his bill in July, his energy use had been recalculated using a higher ‘calorific value’ – a measure of heating power – than previously and First Utility wanted an extra £23.19
Ian queried this, and First Utility said that it had performed a ‘credit and re-bill’ on his account to correct any discrepancies that there may have been with previous billing. It later contacted him again and said the increased charge was in fact due to his change of meter.
Our advice on ‘credit and re-bill’

Ian came to us for advice. We said that he should write to First Utility to say that he wasn’t satisfied with its reply, to ask it to justify that its action was legal and to show where its terms and  conditions allowed it to re-bill him. We also advised that he could go to the energy ombudsman if the case wasn’t resolved within eight weeks.
First Utility didn’t reply, so Ian went to the ombudsman. It asked First Utility to explain the charges, to give Ian a written apology and credit his account with £25 as a goodwill gesture. First Utility agreed to this and also refunded the £23.19 recharge. Ian accepted this.
What the law says on amendments to bills
If an energy supplier amends your bill, you are entitled to ask where its terms and conditions authorise it to do so. Energy suppliers are regulated by Ofgem, which aims to protect the interests of consumers. Ofgem requires energy suppliers to comply with its standards of conduct, including investigating any customer complaints in an honest, transparent and professional manner.
If you aren’t satisfied with how your complaint is handled by your supplier, then you can ask the ombudsman to investigate further. The service is free and impartial.
Has your energy bill ever been recalculated? Did you have any difficulties getting answer from your energy supplier?