Energy bills jargon buster
Energy bills can be baffling at the best of times, so we've put together a glossary of terms that you're likely to find either on your bills or across our site. Simply click on the term you need explained and we'll tell you what it all means. If you need any help finding your way around your bill, then you can also check our guide on how to read your energy bills.
Account number
Your account number refers to the account you hold with your energy supplier. This number will be printed on your bill and you will be asked to provide it when you contact your energy supplier.
Calorific Value (CV)
'Calorific Value' (CV) is a scientific term used to describe how much heat is generated when a known volume of gas is completely burned away. Gas passing through the National Grid has a CV of 37.5MH/m3 to 43.0MJ/m3, but the CV for your specific area should be displayed on your gas bill. Put simply - the CV measures how 'useful' your gas is, so your supplier can charge you based on the quality of the gas that is supplied to you. For more information on calorific values and how they're calculated, please refer to the National Grid website.
Discounts
If you have any discounts applied to your energy bills, they should be marked clearly near the final total. There is a large range of discounts available (common examples include dual fuel discounts and direct debit discounts), so if you're not sure which discounts you're entitled to, you can run through our energy calculator and check your current plan details or contact your energy supplier for more information.
Dual Fuel
Economy 7
Economy 7 is a type of electricity tariff that uses different prices for the electricity you use during the day and the electricity you use during the night. Typically the electricity you use at night will cost you less than electricity used during the day. With Economy 7, the 'night' usually refers to the early hours, between around 1am to 8am, but these hours can vary between suppliers. Read more about Economy 7.
Economy 10
Economy 10 is a type of electricity tariff that charges discounted prices for the electricity you use during 10 set off-peak hours. This structure gives you three off-peak hours in the afternoon, two in the evening and five hours overnight. The designated hours will change between suppliers. Unfortunately we cannot support economy 10 switching on uSwitch.
Estimated (E) or actual (A) readings
If your meter reading has been estimated - then your energy supplier has assumed your usage for the period in question, based on your energy usage patterns in the past. If they don't hold this information, they will use national average figures. If you've had a meter reading recently, then your usage will be marked as 'actual' and not estimated. This isn't always obvious - and might only be denoted by a capital 'A' for 'actual' or 'E' for 'estimated'.
Fixed Monthly Direct Debit (MDD)
If you hold a monthly direct debit with your supplier, then you will pay a set amount to your supplier every month. However this does not mean that your energy prices are fixed. Your energy supplier needs to give you notice if they intend to change the amount of the monthly direct debit.
How to convert units to kWh
On your energy bill, your gas units will be converted to kilowatt hours. Please note that the Calorific Value will change depending on your area - so please check your bill for the correct figure.
Use the following formula to convert units to kWh:
Total units used x metric conversion factor (2.83) x volume conversion factor (1.02264) x calorific value / kilowatt hour conversion factor (3.6).
This works for meters that record hundreds of cubic feet where your gas meter shows 'ft3' next to the reading. If your meter measures in cubic meters with an 'm3' next to the reading, then go through the same sum while removing the metric conversion factor of 2.83.
Example for meter that records hundreds of cubic feet:
1 unit x 2.83 x 1.02264 x 39.1 / 3.6 = 31.43 kWh
Example for meter that records cubic meters:
1 unit x 1.02264 x 39.1 / 3.6 = 11.11 kWh
IGT Network/charges
IGT stands for 'Independent Gas Transporter'. If your home is supplied by an Independent Gas Transporter Network, it means that it is not connected to the National Grid, which supplies most of the UK's home's with gas. You will often find an extra charge applied to your bill if you are supplied by an IGT network, due to the extra costs involved in having your gas delivered. If your MPRN number is 10 digits long and begins with 74 or 75 then you are supplied by an IGT.
Kilowatt hours (kWh)
A kilowatt hour is the standard measurement of energy that your energy supplier will use to bill you. A kilowatt hour refers to a person using 1000 watts of electricity for 1 hour. Your prices will be set per kilowatt hour (kWh) of energy you use.
Loyalty points
Loyalty points will only apply to certain tariffs, and can come in different formats. Sainsbury's Nectar Points and Tesco Clubcard points can be earned on energy bills with suppliers who have a commercial arrangement with specific supermarkets. The number of points you've accrued on your bill should be displayed clearly.
Meter point administration number (MPAN)
Your meter point administration number will often be referred to as your MPAN or your supply number. It can also be referred to as your 'S' number. This number is assigned to the electricity meter at your property to identify it, and can be found on your electricity bill. It is displayed in a very specific format as pictured below:
If you can't find your supply number anywhere, your energy supplier should be able to help you.
Meter point reference number (MPRN)
Your meter point reference number will often be referred to as your MPRN number. This number is assigned to the gas meter at your property, and can be between 6 and 10 digits long. On your bill this number may be referred to as an 'M' number, but if you can't find it you can call the Meter Number Helpline on 0870 608 1524 for help.
Metric conversion factor
MPRN/MPAN
NSC - No Standing Charge
If you plan name includes the abbreviation 'NSC' or the words 'No Standing Charge', then your supplier does not apply a fixed charge to your plan.
Plan/tariff name
The name of your energy plan identifies which tariff you are on, which in turn dictates the prices you are charged. There are hundreds of different plans available in the market, and naming conventions will differ between suppliers.
Standing charges
Some energy plans include a standing charge, where a fixed charge is applied to your bill. This does not necessarily mean that the plan is more expensive than a no standing charge plan, as the kilowatt hour (kWh) rates can be lower.
Standing Order
If you hold a standing order with your energy supplier, you have arranged for a fixed amount to be sent from your bank account to pay your energy bill as often as necessary. You have control of this payment method, so your energy supplier cannot change the payments at their end, even with your permission.
Supply number
Tiers
Sometimes your gas and electricity prices are charged using different 'tiers' on your energy bills. This means that you get charged at one rate until you've used a certain amount of energy, and then at a different rate for any energy used over that level. Plans that include a standing charge won't tend to have different tiers, whereas no standing charge plans will, as this is their way of introducing a type of minimum charge.
Units
Although your gas will be charged according to kilowatt hours (kWh) used, your gas will initially be measured in units. This is then converted to kilowatt hours on your bill using a standard formula. Find out how to convert kWh's into units.
Variable Direct Debit (VDD)
If you have a variable direct debit set up with your energy supplier, then you are giving them control over the direct debit. They will amend the amount taken each month to pay off the outstanding bill, and they do not have to give you notice before changing the amount.
VAT
VAT will be charged on top of your total bill at a standard rate of 5% instead of the usual 15%. It is important to note that your gas and electricity bills will show all unit prices before VAT, whereas uSwitch is required to display all unit prices with VAT included. This allows us to make the most accurate and relevant comparison for you.
Volume correction factor
The volume correction factor of 1.02264 takes into account the changes in the volume of gas based on temperature and pressure.