What this guide covers
This guide explains every section of a typical UK domestic energy bill: what each figure means, how to check whether your bill is accurate, what to do if you think it is wrong, and how to find the key reference numbers you need when switching supplier. It is educational information about UK energy billing.
Why reading your bill matters
Most UK households pay their energy bill by monthly direct debit without checking whether the amount bears any relation to their actual consumption. Understanding your bill means you can spot estimated bills that may be building up inaccurate credit or debt, verify that your tariff rates match what you agreed to, find your annual usage figures for comparison purposes, identify your meter reference numbers when switching, and use a direct debit checker to see whether your monthly payment matches your usage.
The main sections of an energy bill
UK energy bills vary in layout between suppliers but all contain the same core information. Here is what each section means.
Your account details
At the top of most bills you will find your account number, the billing period the bill covers, and your supply address. Your account number is your reference for all correspondence with your supplier. Keep it to hand when contacting them.
Billing period
The billing period shows the start and end dates of the period the bill covers. Most suppliers bill monthly or quarterly. Annual statements cover 12 months and show your total spend, your total usage in kWh, and your average daily consumption.
Meter readings
Your bill will show the meter readings used to calculate the amount owed. These are shown as an opening reading (at the start of the billing period) and a closing reading (at the end).
If the readings are shown as Estimated (or marked with an E), the bill has not been calculated from an actual meter reading. It is based on your supplier's estimate of your consumption. Estimated bills can be higher or lower than your actual usage. Submitting a real meter reading will trigger a corrected bill.
If you have a smart meter, readings are submitted automatically and your bill should always show actual rather than estimated figures. If you are switching supplier and unsure about meter requirements, see our guide on do I need a smart meter to switch.
Units used
The difference between the opening and closing meter reading is the number of units you have used in the billing period. For electricity this is already in kilowatt-hours (kWh). For gas the situation is slightly more complex. See the gas section below.
Gas: units and the conversion factor
Gas meters record usage in cubic metres (m3) or, on older meters, in hundreds of cubic feet (CCF). Your bill converts this to kilowatt-hours using a calculation that involves:
Your bill will show the volume used, the calorific value applied (typically around 39 to 40 MJ/m3), the correction factor (typically 1.02264), and the result in kWh. This is the figure your unit rate is applied to.
- The volume of gas used (from your meter readings)
- A calorific value (the energy content of gas, which varies slightly)
- A correction factor (accounting for pressure and temperature)
- Division by 3.6 to convert to kWh
Unit rate
The unit rate is the price per kWh of energy you consume. It is shown in pence per kilowatt-hour (p/kWh). Your bill multiplies your kWh consumption by this rate to calculate the charge for energy used.
Electricity and gas have separate unit rates. Check that the rates shown on your bill match the rates on your tariff confirmation or the tariff details in your online account. If they do not match, contact your supplier. Our guide on understanding unit rates explains how these charges are structured.
Standing charge
The standing charge is a fixed daily charge that appears on your bill regardless of how much energy you use. It is multiplied by the number of days in the billing period. Electricity and gas have separate standing charges. A standing charge calculator can help you see how much this daily fee adds over a billing period or full year.
Your bill will show the daily rate in pence per day and the total for the billing period. Check this against your tariff confirmation to verify it is correct.
VAT
Energy bills in the UK attract VAT at 5%. Your bill will show the subtotal before VAT and the VAT amount separately, or may show the total inclusive of VAT. The 5% rate is lower than the standard 20% VAT rate and applies to domestic energy supply.
Total amount due
The total amount due is the sum of your energy charges plus VAT, adjusted for any credit or debit balance carried forward from a previous billing period.
If your total shows a credit balance (sometimes shown in brackets, in green, or preceded by CR), you have overpaid. Your account is in credit. Your supplier owes you this amount and you can request a refund.
If your total shows a debit balance, you owe this amount. Check whether this is because a direct debit underpayment has accumulated or because of an estimated bill that was lower than actual usage.
Your meter reference numbers
Every gas and electricity meter point in the UK has a unique reference number. You need these when switching supplier.
MPAN: Meter Point Administration Number
Your MPAN (sometimes called your supply number or S number) is a 21-digit number that uniquely identifies your electricity meter point. It appears on your electricity bill, usually in a box or grid layout.
The MPAN is structured as follows: two profile class digits, three meter timeswitch code digits, three line loss factor digits (these are the top line of the S number box), followed by two digits for the distributor ID and thirteen digits for the unique meter point.
When switching supplier you will be asked for your MPAN. The new supplier uses this to identify your supply point and coordinate the switch with the relevant distribution network.
MPRN: Meter Point Reference Number
Your MPRN (sometimes called your meter number or gas supply number) is a 10 to 11 digit number that uniquely identifies your gas supply point. It appears on your gas bill.
If you cannot find your MPRN on your bill, you can call the Meter Point Administration Service on 0870 608 1524 and provide your address to obtain it.
Checking if an estimated bill is correct
If your bill is based on estimated readings, you can check whether the estimate is reasonable by comparing it to your actual meter reading.
Take a meter reading on the day you receive the bill. Compare it to the closing reading shown on the bill. If your actual reading is lower than the estimated reading, the bill has overcharged you. Submitting the real reading will generate a credit. If your actual reading is higher, the bill has undercharged you and you will owe more on the next bill.
Most suppliers allow meter reading submission online, via their app, or by phone. Smart meter customers do not need to submit readings manually.
Annual statements
In addition to regular bills, suppliers must issue an annual statement once per year. This shows your total energy spend for the previous 12 months, your total consumption in kWh for both electricity and gas, your average daily consumption, and your current tariff details.
The annual statement is the most useful document for energy comparison. The annual kWh figures it contains are what comparison tools use to calculate accurate estimated costs for different tariffs. Keep your most recent annual statement accessible when comparing, or enter the kWh totals in an annual bill estimator for a quick cost estimate.
What to do if your bill seems wrong
If a charge on your bill does not match your tariff confirmation or you believe a reading is incorrect:
If you cannot resolve a dispute with your supplier directly, the Energy Ombudsman provides free, independent dispute resolution for domestic customers. The Ombudsman can be reached at energyombudsman.org.
- First, check your meter reading against the figure on the bill. If the meter reading is incorrect, submit an actual reading to your supplier.
- If the unit rate or standing charge does not match your tariff, contact your supplier with your tariff confirmation details. Suppliers are required to apply the rates they agreed with you.