Energy Jargon Explained

It's no secret that energy bills are confusing- most of them have lots of information with very little explanation of terms or pricing. But have no fear- with our helpful glossary of energy terms you'll have that bill jargon-busted and ready to compare energy prices in no time!

Energy Account

Much like your bank account or your mobile phone account, this is your customer record with the energy company. All the information about your gas and electricity usage, your energy tariff, how much gas and electricity you have used, how much you owe and how you would like the company to contact you is kept here.

Energy Account number

Again, just like your mobile phone account, each gas and electricity customer has a unique reference number. This is the quickest way for the energy supplier to identify you if you need to speak to them, and is found on the top of most correspondence they send you.


Your bill is the breakdown of how much energy you have used, and what this has cost you. It is worked out from your meter readings, either estimated or the actual readings if you have provided these.

Billing period

This is the date range that has been used to calculate what you owe. So if the billing period is over the winter months, it will normally be a higher bill than if the billing period is over the summer months, as you will probably have used more energy.


Like your bank balance, this is a record of how much you owe (or if you are lucky, how much the company owes you!).

Calorific value

This relates to the gas you use, and is a measure of how much heating power your gas contains. The calorific value will be the amount of energy that is released upon combustion of a unit of gas. The calorific value is used to bill you, as it denotes the quality of the gas you use.

Capped price tariff

Capped price tariffs can potentially offer the best of both worlds. If you have signed up to one of these, then the unit price you pay for your energy will not rise above a certain amount. However if the unit price falls, then the amount that you pay should also fall in line with the price drop. These types of tariffs can sometimes be a little more expensive to begin with, so the best way to find out if a capped tariff is right for you is to use our comparison tool.

Consumer Focus

Consumer Focus are the statutory consumer organisation for England, Wales and Scotland. They work across many industries; with regards to gas and electricity their remit is to produce research, investigate suppliers and to raise "super complaints" on behalf of consumers if they deem this necessary. Consumer Focus do not have the power to fine suppliers.


Your consumption is the sum total of the units of energy used in a stated period, or in other words: how much energy you have consumed. The standard measure of consumption is kilowatt hours (kWh). If you are using your kWh consumption to get a quote for your gas and electricity then it is always best to use an annual figure, as your consumption will change seasonally.


Your energy will always be provided through a legal contract. The contract sets out the prices you will pay, the way you will pay and the terms and conditions of your supply. You should be sent a copy of your contract every time you switch energy supplier (or if you are moving house and sign up with the current supplier).

Credit Meter

This is the meter that most people have in their homes. It allows you to use energy before you have paid for it, hence the term 'Credit'. If you have this type of meter, you will pay either by direct debit, or cash or cheque on receipt of the bill. This type of meter is different to a prepayment meter, where you have to pay for the energy you use as you go along, either by putting money straight into the meter or by putting money on to a card and swiping this on your meter. Note that a so-called 'Smart Meter' is not a meter type per se, these meters are called smart because they are built to communicate directly with the energy supplier. A smart meter could be configured as a credit or a prepayment meter type.

Deemed Contract

This contract applies when you move into a new home, and have not proactively signed up for a new supply of gas and electricity. In such circumstances you will be 'deemed' to have automatically taken over the contract with the gas or electricity supplier of the previous occupant. You will, by default be placed on a 'deemed tariff' with that supplier, which is either their standard credit rate or a specially inflated tariff which could be 30%+ more expensive than that supplier's most competitive offer.

Direct debit

This is a payment method whereby money is taken directly out of your bank to cover your energy bills. This could be on a monthly or quarterly basis. Direct debits with energy companies can either be fixed or variable- a fixed one will take the same amount out each time, which could lead to either you owing money, or to you paying too much and building up credit with your supplier. If you pay by this method you should keep an eye on the balance of your bill to make sure that you direct debit amount is regularly adjusted according to how much debt or credit you are accumulating on your account.


Disconnection is a scary word which means that your supplier will stop providing you with energy. This is used as an absolute last resort if customers refuse to pay their bills, and can nearly always be avoided by speaking to your supplier and coming to an arrangement with them. If you move into a property that has been disconnected then you will need to contact the supplier and ask them to switch it back on. If you cannot find out who the supplier is (ask the landlord / estate agent or look for a letter from the supplier in the property) then you can call your Distribution Network Operator (DNO) on the number below who will be able to assist.

Area Company Telephone No
North Scotland Scottish & Southern Energy 0800 048 3515
South Scotland Scottish Power Energy Networks 0141 614 0145
North East England Northern Powergrid 0845 0702703
North West Electricity North West Ltd 0800 048 1820
Yorkshire Northern Powergrid 0845 0702703
East Midlands Western Power Distribution 0845 724 0240
West Midlands Western Power Distribution 0845 724 0240
Eastern England UK Power Networks 0845 601 4516
South Wales Western Power Distribution 0845 724 0240
Southern England Scottish & Southern Energy 0800 048 3516
London UK Power Networks 0845 601 4516
South East England UK Power Networks 0845 601 4516
South West England Western Power Distribution 0845 724 0240
North Wales, Merseyside
and Cheshire
Scottish Power Energy Networks 0845 270 0783


Discounts can be offered for all sorts of reasons- the most common being dual fuel, monthly direct debit and online discounts. Companies offer discounts to try to persuade you to switch to them and to incentivise you to use your energy account in a certain way, for example, managing it online and therefore saving the company the cost of sending out paper bills.


stands for Distribution Network Operator company. When the energy industry was deregulated in the 1990s, the government separated the generation of energy from the transport of energy. The DNO is the company that has the license to maintain the electricity infrastructure in your geographic area - wires, cables, sub stations, transformers - the lot. The DNO is not your energy supplier. This can be confusing, because most energy customers instinctively want to call their supplier when the power goes out. For a list of DNO companies see here. See also IDNO

Dual fuel

Dual fuel simply means that both your gas and electricity accounts are with the same supplier and supplied under the same tariff name. But just because you are currently on a dual fuel tariff does not mean that you have to stay on one. It some circumstances it is cheaper to have your accounts with separate suppliers. To find out what is best for you, make a comparison for dual fuel first and then separately for gas and electricity.

Economy 7

Economy 7 electricity is a generic industry term for off-peak (night time) electricity. Because of the peculiar economics of electricity generation, certain large power stations (particularly coal and nuclear) need to run around the clock. They therefore produce electricity at night time when most of us have little need for it. To incentivise night time energy usage, particularly for storage heating, the industry came up with the term Economy (meaning cheap) and 7 (meaning 7 hours at night time) to offload energy that the industry in any case needs to produce. The retail price of each night time unit is approximately one third of the cost of daytime units and can be an effective way of keeping your home warm at lower cost (if you have storage heaters) or heating your water tank.

Economy 10

Like Economy 7, but for 10 hours instead of 7. This type of meter is quite rare and cannot be supported by all suppliers.

Estimated meter reading

Your supplier needs meter readings to be able to bill you. If you have not provided your meter readings your supplier will estimate your average energy usage. This could work out expensive for you if you are a low user, so it is always best to keep your supplier up to date and only pay for what you use.

Fixed tariff

This type of tariff means that the amount you pay for each unit of energy used will remain the same while you are on the tariff. When prices are rising these tariffs are a great way to protect yourself and your wallet, but by signing up to a fixed rate tariff you are taking a gamble that energy prices will not come down and leave you paying over the odds for your gas and electricity. Click here to compare prices for fixed rate tariffs.

Green energy

These are environmentally friendly tariffs. Green energy tariffs currently on offer usually get their green credentials from a combination of the following: supplying electricity from environmentally friendly resources such as wind power, carbon offsetting and investing a portion of profits into environmental projects or technology. It is not possible to have "Green" gas, so some tariffs offer the additional benefit of offsetting your gas usage via carbon offset credits.

Green deal

The Green Deal is a critical part of the UK Government's carbon emission reduction strategy. The Green Deal, which kicked in on January 28th 2013, offers UK home owners access to finance to pay for home insulation projects. Loans are repaid via electricity bills (which will presumably come down as a result of the work). It works like this: you first have your home assessed for potential savings by an official Green Deal Assessor. Once you're agreed on the feasibility and scope of potential improvements you sign on the dotted line of the Green Deal Plan and choose a Green Deal provider to do the work. The provider gets paid in full and you pay it all off over time via your electricity bill. Simple, failsafe and bound to be hugely popular - what could go wrong, right? More information is available on the official Green Deal website...


stands for Independent Distribution Network Operator company. These companies are licensed by the energy markets regulator Ofgem to manage the distribution of electricity. Unlike DNOs who operate within a specific geographic area whose boundaries were defined at the time of deregulation, IDNO's can operate anywhere in the country. IDNOs typically focus on managing electricity distribution for new housing developments, and it is no surprise that building companies have applied for IDNO licenses in the main. Whether you are supplied via a DNO or IDNO is of no real importance to energy consumers as this does not affect your ability to switch energy supplier. Unlike their gas equivalents IGT , IDNOs also cannot levy surcharges. You can tell whether you are on an IDNO network if the second row your MPAN number begins with the number 24 or higher. DNO


IGT stands for Independent Gas Transporter. These are companies that hold a license from the regulator Ofgem to ship gas to your home. IGTs are therefore not gas suppliers, but charged with maintaining the necessary infrastructure for getting the gas to your home. Unlike their equivalents on the electricity side (see IDNO ), IGTs can charge more than their national counterpart Network Grid for this service, and many gas suppliers will pass this surcharge on to their customers. If your MPRN starts with the numbers 74 or 75, that means that the gas connection to your property is maintained by an IGT. You can still switch supplier as much as you like though!

kWh (Kilowatt hour)

This is the billing unit for the energy you have used. Your consumption is measured in kWh, and your bill provides you with a breakdown of how many of those you have used, what price they have been charged at, and how much this has cost you in total.

M Number


Meter Readings

These are used to measure your energy consumption, and are taken from left to right. If you have a dial meter, you should only have to read the first 5 digits, and if you have a digital meter you should read all 6. On your bill you may see "previous reading" which refers to the meter reading you submitted before the reading that you are being billed for. The "most recent reading" is what you will be paying for.


This stands for "meter point administration number" (sometimes called your "supply number" or "S number"), and is the unique reference number for your meter. Energy companies may sometimes need this to be able to switch you over so if you are making a comparison then it would be helpful to have it to hand. Your MPAN can be found on your electricity bill (or can be given to you by your supplier) and will typically look like this:


MPAS means Meter Point Administration Service. This is the department at your energy supplier that maintains the connection between your home and the gas and electricity grids.

Network Grid

This is the company that was created at the start of deregulation in the 1990s when the original British Gas was broken up into a supply company and an infrastructure company. Network Grid is responsible for maintaining most of the gas infrastructure, like pipelines and gas storage facilities in Great Britain. See also IGT


Like your MPAN but for your gas (it will sometimes be called your "M" number), and only 8-10 digits long. Your supplier will be able to tell you what this number is for your property if you cannot find it on a bill.


The Ombudsman Service is an independent dispute-resolution organisation that was established by an act of Parliament. It is free to use and (even better) its decision is binding on energy suppliers. If you feel that the supplier has not resolved a complaint to your satisfaction within eight weeks, you can take your complaint to the Energy Ombudsman Service. Note that you have to give the process eight weeks and that you cannot start the complaints process by going to the Ombudsman Service first. To contact the Ombudsman Service, go to this site .


Ofgem, the Office of Gas and Electricity Markets is the regulator of the gas and electricity industries in Great Britain. New suppliers need to be licensed by Ofgem before they can supply you with gas and/or electricity. It is one of Ofgem's roles to ensure that licensed energy suppliers can meet their customers energy needs. Ofgem was formed in June 1999 by combining the functions and operations of the former gas regulator OFGAS (Office of Gas Supply), and the former electricity industry regulator OFFER (Office of Electricity Regulation). It has over 300 employees. Ofgem was set up by the government to protect the interests of all gas and electricity customers ensuring that they get genuine choice and value, to promote effective competition in the production, distribution and supply of gas and electricity, and to regulate the gas and electricity industries throughout Great Britain. Ofgem can be contacted by telephone on 020 7901 7000, or by post at Ofgem, 9 Millbank, London SW1P 3GE.

Online tariff

This refers to a type of tariff where you manage your account online. It will usually mean that you have to have to accept paperless billing as a condition of supply.

Prepayment meter

This type of meter is one where you have to pay for your energy before you use it, by topping up a payment card or putting money into the meter itself. Landlords sometimes install these types of meters to avoid being left with a hefty bill after a tenant has left, and energy companies can choose to install these if a customer often slips behind on their bills. Prepayment meters are usually more expensive than credit meters, so if you find you have one in your home then ask your energy supplier to change it for a credit meter. They may charge you for this but you should regain the money through lower bills.

Rolling Contract

This type of contract is one that will carry on until you choose to change it or switch energy supplier, for example a standard contract. This kind of contract is also sometimes called 'Evergreen'.

Standing charge

This is a daily charge that you will be incurring even without using any energy. Many people who have low usage prefer to be on a no standing charge tariff, as otherwise they may be paying more than they need to for their energy. If you see the abbreviation "NSC" on your bill or on a comparison site, then this will mean no standing charge. If you are on a tariff that has a standing charge, you may find that your unit price is lower so you will in fact be paying the same amount for your energy as someone on the NSC version of the tariff. The best way to find out if you are on the correct plan for your energy profile is to make a comparison.

Supply number



This is the process of changing either your energy supplier, or the tariff that you are on with your current supplier. Suppliers are constantly releasing new tariffs so even if you have switched before, you could save even more money by switching again. Just use our energy comparison tool to see how much you could save.

Tariff/ Tariff Plan

The pricing plan that sets out the price you will pay for your gas and electricity, the way you will pay, and the discounts that you are entitled to. Suppliers have many different energy tariffs, which can be confusing, but it is an important piece of information to know as a customer. If you would like to make a comparison to switch suppliers, you will need to have this to hand.


Some tariffs offered by suppliers divide the energy you use into blocks. So for example, the first 2680 KWH of gas you use may be charged at one price, and then anything you use over this amount is charged at a second (usually cheaper) price.


The unit for measuring your gas and electricity is a kilowatt hour, which is approximately 3600 kilojoules.

Usage Profile

Usage profiles are set by Ofgem, and are broken down into low, medium and high use.
Low: 11,000 KWH for gas and 2,100 KWH for electricity. Typically a small flat, with single occupant or a couple.
Medium: 16,500 KWH for gas and 3,300 for electricity. Typically a small family or couple in a semi-detached house.
High: 23,000 for gas and 5,100 for electricity. These users would be larger families, in detached houses with 3 or more bedrooms.


VAT (or Value Added Tax) is charged on most commodities (but not pasties!). It is added to your energy bill at a rate of 5%.

Vulnerable Customer

This term is used to describe those customers who may need more assistance with their energy bills, or their energy supply. People who may fall into this category are the elderly, the chronically sick or disabled, and those on a low income or benefits. Each supplier has different criteria to establish if someone is a vulnerable customer or not, so if you think you may be eligible for help then please give your provider a call.

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