The average UK household paid £1,738 for gas and electricity in 2023 — and some are still being chased for bills from two or three years ago. Ofgem’s backbilling rules, updated in 2022, now give homeowners a clearer right to challenge those charges.
As reported by Wales Online, Ofgem has clarified that suppliers cannot bill you for energy used more than 12 months ago unless they can prove you deliberately stopped them from reading your meter. That’s a shift from the old 12-month limit, which suppliers sometimes dodged by claiming meter access was blocked.
Who qualifies — and who doesn’t
The backbilling rule applies to any domestic electricity or gas customer in Great Britain. It covers estimated bills, misread meters, supplier data errors, and even cases where the supplier failed to bill you at all for months or years. If you receive a bill for energy used more than 12 months ago, you can dispute it on these grounds.
But there are exceptions. The rule does not apply if you have deliberately prevented the supplier from reading your meter — for example, by locking the meter box or refusing access. It also doesn’t cover cases where you have been found to have tampered with the meter or committed fraud. Nor does it apply to business customers. If you’re on a prepayment meter, the rule works slightly differently: you can only claim back charges for energy used more than 12 months ago if the supplier failed to install the meter correctly or made an error in your account.
What it means for your household budget
For a typical 3-bed semi using 12,000 kWh of gas and 3,000 kWh of electricity per year, a backdated bill for two years of undercharging could easily top £3,000. Under the backbilling rule, you would only owe the last 12 months — potentially saving you £1,500 or more. The catch is that you must act promptly. The rule does not automatically trigger refunds; you have to identify the error and request the refund from your supplier.
Ofgem requires suppliers to process refunds within 10 working days of a valid claim. If they refuse, you can escalate to the Energy Ombudsman. The process is free, though it can take several weeks. The Energy Saving Trust recommends keeping all bills and meter readings for at least two years to build a clear paper trail.
How to check and claim
Start by reviewing your energy bills from the past 24 months. Look for any charges that appear to cover periods older than 12 months from the date of the bill. If you find one, write to your supplier stating that you are invoking the backbilling rule and requesting a refund for the amount over the 12-month limit. Include your meter readings and any evidence that the supplier had access to your meter.
If your supplier rejects your claim, contact the Energy Ombudsman. Ofgem’s own enforcement data shows that between 2021 and 2023, suppliers paid out over £18 million in backbilling refunds — so the rule is being used. But the onus is on you to spot the error. Check your bills now, before the next price cap change in April 2025 pushes typical bills up again by around £25 a year.
Frequently Asked Questions
You can claim a refund for any energy charges that were billed more than 12 months after the energy was used. The rule covers estimated bills, misread meters, and supplier errors. If the supplier can prove you deliberately blocked meter access, the rule does not apply.
If your supplier rejects your backbilling claim, you can escalate the dispute to the Energy Ombudsman. The process is free, and Ofgem requires suppliers to comply with the ombudsman's decision. You should keep all correspondence and meter readings as evidence.
