Start with the bill's supply address and billing period, then check how many kilowatt-hours (kWh) were charged, the unit rates and standing charge. Finally, look at tax, adjustments and contract details. Separate each fuel and each rate period before comparing bills or quotes.
1. Confirm the premises and dates
Check the address, meter or supply identifiers, fuel and dates covered. Make sure the account relates to the right site and that any opening or closing meter reading matches what you recorded. Note whether a reading is actual, customer-provided or estimated.
If a bill covers only part of a year, do not compare its total directly with a full-year quote. A winter month and a summer month can have very different usage.
2. Find the kWh and unit rate
A unit rate is what the contract charges for each unit of energy, usually shown in pence per kWh. Bills can show several readings, time bands or rates. Keep those lines separate rather than averaging them unless you know the calculation.
As a check, multiply the kWh in each rate band by its price per kWh, then compare with the energy-charge line. Small rounding or adjustments may apply; ask the supplier about unexplained differences.
3. Add the standing charge
The standing charge is a separate daily cost for the supply, usually payable whether or not energy was used. Multiply the daily amount by the number of billed days to understand its effect. A lower unit price can still lead to a higher bill if the standing charge or fees are higher.
4. Check taxes and other adjustments
Look for VAT and, where relevant, Climate Change Levy (CCL), alongside any other listed charges or credits. Tax treatment can depend on your circumstances, so do not infer your VAT or CCL status from another business's bill. Ask the supplier or a qualified tax adviser if unsure.
Check any discounts, refunds, late-payment charges and prior-period corrections. Ask for an explanation if an adjustment is unclear.
5. Compare the contract, not just this bill
Use the contract to verify the agreed rate, end date, notice window, renewal arrangements and any exit fees. Then compare a potential quote using equivalent annual kWh, the same supply address, term, standing charge and tax basis. Ask whether any intermediary fee or broker commission sits within a quoted rate.
The business energy estimator can help turn annual usage into an indicative comparison. It uses fixed reference assumptions, not live supplier prices.
Keep copies of bills and written explanations. If a reading or charge seems wrong, contact the supplier promptly and retain the response.