Understanding your energy bill

You should receive energy bills at least every quarter

Most energy suppliers send bills in the post, or via email, at least every quarter - but the information on a typical bill can be a minefield of confusing terms and jargon. Here's what you need to know to check your energy bill is accurate.

What all energy bills contain

Your name, address and date.
Customer account or reference number (always quote this when you contact your energy supplier).
Your energy supplier (e.g. British Gas) and its contact details.
Name of your gas or electricity tariff or plan.
How much you need to pay (including any money owed from previous bills) and when you need to pay by.
Meter number.
Billing period: the period in which you used the energy you're being charged for.
Meter readings: the difference between the previous and latest reading is the amount of energy (measured in kilowatt hours or kWh) you've used.
Amount your supplier is charging you for each kWh of gas or electricity.

If you pay a standing charge (which covers things like meter readings and the cost of keeping you connected to the network) you'll pay a single rate; if not then you will pay a higher price for a given number of energy units and then a lower rate thereafter.

If you're switching supplier

Note down the following from your recent energy bills before switching energy suppliers:

1. Name of your supplier.

2. Name of tariff / plan.

3. Amount of gas and electricity you've used in kilowatt hours (kWh) - calculate an annual or six month figure using recent bills.

You can also find your MPAN number for electricity, and MPRN number for gas, on your bill. These unique reference numbers identify the meter at your property. If your exact meter can't be located when switching energy suppliers, we'll ask you for this number instead.

Gas and electricity meter readings

You can check whether your energy bill is based on a gas or electricity meter reading taken by either you (usually indicated by the letter 'C' for customer) or your energy supplier ('A' for actual) - or whether it's an estimated reading calculated by your energy supplier ('E').

Check your energy bills are based on meter readings

If your energy bill is based on an estimated meter reading you should read your gas or electricity meter yourself and provide this information to your energy supplier, so it can send you a revised gas or electricity bill, based on your actual usage.

We suggest you read your own gas and electricity meters every three months.

Paying energy bills by direct debit

If you pay by monthly direct debit, you'll still receive a regular bill. Your supplier works out how much you spend on energy in a year and divides this up into equal monthly payments. Energy suppliers often offer a discount if you pay in this way, because it guarantees payment to them, but there are lots of other ways you can pay your energy bill.

You should keep a regular check on your bills to make sure your supplier is asking you to pay the right amount. Bear in mind that because energy use is not equal throughout the year, direct debit customers effectively underpay in winter and overpay in summer - but it's sensible to question any particularly large credit or debit balances with your supplier.

If you don't think you're paying the correct amount, contact your energy supplier to ask for a breakdown of how your direct debit amount is calculated. See our how to complain guide to help you resolve utility bill discrepancies.

Energy bill breakdown

The cost of a domestic energy bill is made up of several different elements. Prices aren't regulated, but are monitored by energy regulator Ofgem. These figures show how a typical gas and electricity bill breaks down.

Understanding your energy bill
Energy bill breakdown	Electricity bill	Gas bill
Wholesale energy costs and your supplier's margin	69%	74%
Distribution	15%	15%
Investment in greener energy	8%	3%
VAT	5%	5%
Transmission	3%	2%
Meter provision	1%	2%

Calculating gas use

Most people use more energy in the winter months for heating and lighting

Although gas meters measure the amount of gas used in cubic feet or cubic meters, gas bills display your use in kilowatt hours (kWh). The industry standard formula for converting cubic measurements to kWh is as follows.

Subtract your current gas meter reading from your previous reading to work out how many cubic meters or feet you have used.
If your measure is in cubic feet, multiply by 2.83 to convert to meters.
Multiply by 1.02264.
Multiply by the 'calorific value' (find this on your bill, or ask your gas supplier).
Divide by 3.6 to work out your kWh figure
Multiply the kWh figure by your pence per kWh rate (find this on your bill, or ask your gas supplier) to give the cost of gas used.

Cutting your energy bills

Switching to a different supplier and tariff - or simply choosing to pay your existing one by direct debit, or managing your bills online - could cut your gas and electricity bills.

With Which? Switch, you can compare the latest deals from all the major suppliers - have your recent energy bills to hand while you're running a comparison to get results specifically tailored to you.

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