Before You Pay That Energy Bill: A Householder's Audit in Six Steps

The average dual-fuel household in Britain now spends well over £1,300 a year on gas and electricity, yet few of us read the bill with anything like the attention we'd give a payslip. Suppliers know this. Errors — from stale meter readings to quietly lapsed discounts — are rarely corrected unless the customer spots them first.

The good news: auditing an energy bill takes about twenty minutes, requires no specialist knowledge, and can recover real money. Here's how to do it properly.

Step One: Check Whether the Readings Are Real

The single most common billing error is the estimated reading. Look for the word "estimated" or an "E" beside the meter figures. Estimated readings are guesses based on your historical usage and the season — and they're frequently wrong.

Take a photo of your meter on the day you audit. If the billed figure doesn't match what's on the meter, submit the actual reading through your supplier's app or website. Under Ofgem's rules, suppliers must accept accurate readings and rebill accordingly.

Step Two: Verify the Unit Rate and Standing Charge

Your bill should state a unit rate (pence per kWh) and a standing charge (a fixed daily amount). Compare both against the tariff you signed up for, and against Ofgem's current price cap for your region and payment method.

Two things to watch:

• Tariff expiry. Fixed deals end silently. If your rate has jumped to the supplier's standard variable tariff, you may be able to switch — or claim the rate you were promised if a fix was mis-sold.
• Payment method discrepancies. Prepayment and standard credit customers typically pay more than direct debit customers. Ensure you're being charged for the method you actually use.

Step Three: Sanity-Check the Consumption

Divide the billed kWh by the number of days in the billing period. A typical household uses roughly 7–9 kWh of electricity and 24–27 kWh of gas per day, though this varies enormously. A sudden spike with no change in your habits deserves an explanation — it may indicate a billing error, a faulty meter, or in rare cases, a neighbour's supply crossed with yours.

Step Four: Hunt for Back-Billing

A back-bill is a charge for energy used more than twelve months ago. Ofgem's back-billing rules state that suppliers should not bill for consumption older than twelve months where the customer has taken reasonable steps — such as providing readings — and the delay was the supplier's fault.

If a back-bill appears, ask the supplier in writing to confirm why the charge wasn't billed earlier and to evidence the readings used. Many back-bills are reduced or withdrawn on challenge.

Step Five: Complain Formally First

Before escalating, give the supplier a chance to fix it. Complain in writing (email is fine), state the specific error, the correction you seek, and a deadline of eight weeks. Suppliers must issue a written response — a "final decision letter" — within that period.

Keep everything. Screenshots, meter photos, and copies of correspondence form the backbone of any ombudsman case.

Step Six: Take It to the Energy Ombudsman

If eight weeks pass without resolution, or you're unhappy with the final response, the Energy Ombudsman can investigate free of charge. It has the power to order corrections to your bill, apology letters, and compensation of up to £10,000 in appropriate cases.

Typical outcomes are modest but real: corrected bills, refunds of overcharges, and goodwill payments commonly ranging from £50 to a few hundred pounds depending on the seriousness of the failure. The decision is binding on the supplier — but not on you, so you can still pursue the matter elsewhere if you disagree.

The Habit That Pays

Photograph your meters monthly. Submit readings at the same time. Reconcile your direct debit against actual usage once a quarter. It's a small routine, but it's the difference between paying what you owe and paying what you're told.