UK Energy Bill Overcharge: How to Dispute and Get Your Money Back

Why UK energy bills go wrong more often than you think

Estimated meter readings are the single biggest cause of UK energy overcharges. When your supplier cannot access your meter, they guess your usage based on averages. When an actual read eventually happens, the reconciliation can produce a shockingly large bill. Ofgem — the UK energy regulator — received tens of thousands of billing complaints last year. You are not alone, and you have rights.

Step 1: Identify the exact error on your bill

Before contacting your supplier, know exactly what you are disputing. UK energy bills must show the read type for each meter reading: 'A' (actual), 'E' (estimated), or 'C' (customer submitted). Find the error type first.

• Look for 'E' or 'Estimated' next to meter readings — this means your bill was based on a guess
• Check the tariff applied matches what you signed up for
• Back billing: under Ofgem rules, suppliers cannot charge for energy used more than 12 months ago if the error was their fault
• Check the unit rate and standing charge against your contract

Step 2: Submit your own meter reading immediately

If the problem is estimated readings, submit your actual meter reading via your supplier's app or website right now. This creates an official record with a timestamp. Take a photo of your meter showing the reading and the date. This is your primary evidence.

• Submit via the supplier's online portal or app — get a confirmation number
• Photograph the meter display clearly with today's date visible
• If you have a smart meter, request your half-hourly data download

Step 3: Make a formal complaint to your supplier

UK suppliers are legally required to have a complaints process. Contact them in writing — email is better than phone because it creates a paper trail. State the exact amount you believe is incorrect and provide your evidence. Under Ofgem's rules, they must respond meaningfully within 8 weeks.

• Write 'Formal Complaint' clearly in the subject line
• State the billing period, the amount disputed, and the reason
• Attach photos of your meter reading and any relevant bills
• Keep every email and reference number

Step 4: Escalate to the Energy Ombudsman if needed

If your supplier does not resolve the complaint within 8 weeks — or gives you a final response you disagree with — you can escalate to the Energy Ombudsman for free. The Ombudsman can force your supplier to issue a refund, a written apology, or a goodwill payment. In 2024, the Ombudsman upheld over 40% of consumer complaints.

• You can contact the Ombudsman after 8 weeks of no resolution, or after receiving a 'deadlock letter'
• The service is free for consumers
• The Ombudsman's decisions are binding on the supplier
• Visit energyombudsman.org to start your case

The Ofgem back billing rule: your most powerful protection

Since 2018, Ofgem rules state that if your supplier failed to bill you correctly for more than 12 months — and the error was on their side — they cannot charge you for that period. If you have received a large catch-up bill that covers more than 12 months of underbilling, challenge it immediately with this rule. Suppliers are required to waive the out-of-date portion.