I Want to Complain About My Energy Supplier
If your energy supplier has let you down — incorrect bills, poor customer service, failed switching, or supply problems — here is how to resolve it step by step.
Estimated timeline
Energy suppliers must publish their complaints procedure on their website (Ofgem requires this under the Standards of Conduct). Find the link, send your complaint by email or via the online form so you have a written record, and reference "this is a formal complaint" so it gets logged correctly. State (a) what went wrong, (b) when, (c) what you want them to do (apologise, correct the bill, pay compensation, restore supply), and (d) any deadline you propose. The supplier must acknowledge within 5 working days and aim to resolve within 8 weeks. Keep your reference number — you will need it for every later step.
The supplier has up to 8 weeks from the date you complained to give you a final response. Many resolve faster. Watch for: (i) an offer of resolution that you can accept or reject, (ii) an explanation of why they are not upholding the complaint, or (iii) a deadlock letter saying they cannot do more. During this period the supplier should not chase you for disputed amounts. If they continue to issue threatening letters or pursue debt collection on amounts you are formally disputing, that is itself a breach of the Standards of Conduct that you can include in your complaint.
A "deadlock letter" is a written confirmation that the supplier considers the complaint at a standstill — they will not move further. Two routes get you to the Energy Ombudsman: (a) the supplier issues a deadlock letter (any time), or (b) 8 weeks pass without a final response. If you are stuck in repeated back-and-forth and the supplier refuses to issue a deadlock letter, ask in writing: "Please confirm whether this is your final response, and if so, please issue a deadlock letter so I can refer the complaint to the Energy Ombudsman." Keep a copy of the request — that itself becomes evidence.
Build a single PDF or folder containing: copies of disputed bills (especially the ones showing the issue and the most recent one), all email correspondence with the supplier, your timeline of events as a numbered list (date — what happened — your reference number for that exchange), any photos (faulty meter, damaged property, smart-meter installation issues), meter readings you have submitted, the deadlock or final response letter, and your written calculation of any financial loss (e.g. extra cost of running heaters in winter without supply). The Energy Ombudsman makes decisions on documents, not phone calls — strong evidence is decisive.
Submit at <strong>energyombudsman.org</strong> via the online form, by post, or by phone (0330 440 1624). The service is free for consumers. You can also use it for micro-business disputes. The Ombudsman will: (i) confirm receipt within 5 working days, (ii) ask the supplier for its evidence and case file, (iii) propose a resolution. Most cases resolve in 6–8 weeks; complex ones can take longer. Possible remedies: an apology, a correction to your account or bills, an explanation, action to fix the underlying issue, and a financial award (up to £10,000 for consumers). The Ombudsman's decision is binding on the supplier if you accept it but not on you — if you reject it, you keep the option of court action.
Frequently asked questions
Does it cost anything to use the Energy Ombudsman?
Can I switch supplier while my complaint is open?
What if I disagree with the Ombudsman's decision?
Official bodies and resources
Energy Ombudsman
OmbudsmanResolves complaints between energy consumers and suppliers, including gas and electricity companies.
Office of Gas and Electricity Markets
RegulatorThe energy regulator for Great Britain, protecting consumers by working to deliver a greener, fairer energy system.
Citizens Advice
CharityProvides free, confidential, and independent advice on a wide range of issues including benefits, housing, debt, and employment.
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