Gas and Electricity Frequently Asked Questions

Switch today and save £491*

in partnership with Banner_uswitch

Looking to switch your business energy supplier? Click here

* Between April 1, 2017 and September 30, 2017, at least 10% of people who switched energy supplier for both gas & electricity with saved £491 or more.*

This page will assist in finding answers to questions you have about switching suppliers. It also provides information about this site.

Gas and Electricity Suppliers and Tariffs

Gas and Electricity Meters and Numbers

Gas and Electricity Industry

Switching Gas and Electricity Supplier

Gas and Electricity Suppliers and Tariffs

Tariffs Used in Databases

All gas and electricity tariffs shown in the results tables are currently available energy tariffs. We assume that you are on a current tariff and not a historical tariff no longer available from the supplier. Please bear in mind that this may impact upon the calculations given.

In order to compare prices, it is best to enter the number of kilowatt hours that you use as opposed to the amount of money you spend. If you do not have the kWhs, then you can enter the amounts you pay monthly, quarterly or annually. When you do this, the calculator works out how many kWh's you use, but it uses the latest available tariffs to do this and does not take into account any changes to the rates for that tariff. It will then use the calculated number of kWh's to work out what each supplier will charge for the next 12 months based on existing tariffs. The results page shows how the suppliers compare to each other for the same amount of energy used.

Back to top

Tariff Details

The detailed tariff information for each supplier tariff is found by clicking on the tariff name or on 'view tariff information label' in the results table. This page will show all unit rates, details of any primary or secondary units and their thresholds and details of any discounts or charges and the Terms & Conditions.

Back to top

Late Payment Penalty Charges

Some suppliers will charge extra penalty charges for late payments. These extra penalty charges are not included in these price comparisons.

Some suppliers will charge for cheque payments. Where this applies, an extra charge is included in the prices and this is noted in the suppliers information box.

The calculations on this website assume that customers are taking advantage of the best options available, and that no extra charges are included for late payments or payments by means which cause surcharges.

Back to top

Prompt Pay Discounts

These calculators do not assume that you are taking advantage of any discounts for prompt payment on standard credit accounts.

Back to top


All prices used on this on the domestic calculator include VAT at the prevailing rate. Rates quoted for business gas and electricity exclude VAT.

Back to top

How often is the website updated?

Each time we receive an update from a supplier, whether it is in respect of a new tariff being launched or a price update on an existing tariff, our website is updated. This usually happens within one to two hours of our receiving the information from the supplier.

Details of all updates can be found on our Prices Updates page

Back to top

Supplier Ratings

One factor to consider when switching your energy supplier is the levels of service and customer satisfaction. and Ofgem are all keen to promote the needs for high standards of customer service.

The ratings given on this website are the results of customer surveys carried out by the independent company J.D. Power. Neither or any of the energy suppliers have any influence over the outcome of these surveys.

Back to top

Non cash incentives for signing up with new suppliers

Some suppliers offer non cash incentives for signing up. These are not included in these price comparisons.

Back to top

Utility Warehouse (Telecom Plus) tariffs

Utility Warehouse (Telecom Plus ) is a membership organisation which rewards customers who take multiple services from them (gas, electricity, home phone, broadband, mobile).

For further information about joining Utility Warehouse (Telecom Plus), and all the rates and benefits available on telephones, Mobile Phones, Freephones as well as Gas and Electricity, please click here .

Visit the Utility Warehouse (Telecom Plus) website

Back to top

Economy 7 – when are the off-peak hours?

The times vary between regions and sometimes even between properties. Therefore you will need to contact your supplier to find out exactly when your off-peak hours are. Read more about Economy 7 here

Back to top

Restricted Hour Tariffs (RHTs)

Restricted Hour Tariffs (RHTs) exist in some properties where there is more than one meter. Energy is only available through each meter at certain times of the day, and is charged at a different rate for each meter. do not compare RHTs, but please see the table below for information concerning the policy of all the major suppliers:

Supplier RHT Policy
British Gas RHTs are not supported for new customers.
E.ON RHTs are supported to new customers in areas with no mains gas.
EDF RHTs are not supported for new customers.
npower RHTs are not supported for new customers.
Scottish Power RHTs are not supported for new customers.
SSE Group RHTs are supported for new customers in certain areas depending on post code.

Last updated: 10 May 2012

Back to top

Gas and Electricity Meters and Numbers

What is the Electricity MPAN or Supply Number?

MPAN stands for Meter Point Administration Number. This number is located on your electricity bill (and not on the meter). It provides a unique identity reference number for the meter and also provides other information about the type of supply.


Domestic meters have a profile of either 01 (standard) or 02 (Economy7). Business meters have a profile of 03 to 08 and half hourly electricity meters have a profile of 00.

When switching the energy supply of your home, we only require the bottom row of figures for your application.

Back to top

How can I tell what Region my electricity supply is in?

If you look at the grid above, you can see the first box on the second line is called "Distributor Identifier". The numbers in this box identify the Region you are in as follows:

  1. Eastern
  2. East Midlands
  3. London
  4. Manweb
  5. Midlands
  6. Northern
  7. Norweb
  1. Scottish Hydro
  2. Scottish Power
  3. Seeboard
  4. Southern
  5. Swalec
  6. Sweb
  7. Yorkshire

Note that when your postcode is close to the border of a region, it is important to check that you are using the correct region for the comparison calculations as the prices vary from region to region and some postcode areas straddle regions.

Back to top

What is the Gas MPR (or 'M number')?

MPR stands for Meter Point Reference. This number is on your gas bill and is sometimes referred to as the M number. It provides a unique identity reference number for the meter and the supply.

Back to top

How can I find out who supplies the gas and electricity to my home?

If you've recently moved home or about to move into a new property, read our guide below to find out who your gas and electricity provider is and how to save on your energy bills once you know.

Find out who your gas and electricity supplier is »

Back to top

How can I find out what my electricity and gas Supply Numbers are?

For most addresses, we will be able to automatically detect your supply numbers when you select your property during the comparison process. For those properties where we do not have your supply number, you should be able to locate them on your gas and electricity bills.

If you do not have previous bills:

Electricity: Where to get your MPAN or Supply Number if you do not have a bill.

If you do not have a bill, contact your regional electricity distributor (who may well be different from your current supplier, but they are still responsible for transporting your electricity). If you call them and ask for the Metering Point Administration Service, they will tell you what your Supply Number is.

Click here to view a list of regional electricity distributors »

Gas: Where to get your MPR Number or 'M' Number if you do not have a bill?

If you do not have a bill, call the M Number Enquiry Line on 0870 608 1524.

Back to top

Equipment maintenance contracts

Some energy suppliers also provide separate contracts for equipment maintenance. The cost of these contracts is excluded from these calculations. Usually, these maintenance contracts are separate from the supply contract, so if the supply contract is changed, this does not affect the maintenance contract which continues. This must be checked to make sure it applies in each case.

Back to top

Independent Gas Transporters (IGTs)

Some properties have private gas pipes which go from the public gas pipes on the main road to your property. These pipelines are operated by Independent Gas Transporters(IGTs). You can find details about these on the Ofgem website at

It should be noted that daily or annual standing charges for gas supplied via IGTs will be charged at higher prices than the standard tariffs. Below is a table which shows information on how much suppliers charge if you have an IGT at your property.

IMPORTANT NOTE. Any additional charges levied by IGTs are not included in the comparison results and should be excluded from the input data.

Energy supplier Approximate charge per year
Atlantic £0
British Gas £0
co-operative energy £0
E.ON £42. Some E.ON tariffs do not have an IGT charge. Where this is the case, it is indicated in the tariff details on our website.
EBICo £0
Ecotricity £0
EDF Energy EDF's IGT charges vary by region
first:utility £0
Good Energy Good Energy does not accept customers supplied by IGTs
M&S Energy £0
npower £10.50
OVO Energy £0
Scottish Power £0
Spark Energy £0
SSE £0
SSE Scottish Hydro £0
SSE Southern Electric £0
Utilita £0
Utility Warehouse (Telecom Plus) £34.2

If the information is out of date please let us know at

Back to top

Converting Units to Kilowatt Hours

Electricity consumption is usually already stated in kilowatt-hours on your meter and previous bills, so the electricity kWh's figure is ready to use.

Gas units as shown on your meter need to be converted to kilowatt hours. Below is a step by step process for calculating kWh:

  Task Sample
1 Number of units 100
2 Convert from imperial to metric (x 2.83) * 283
3 x volume conversion factor (x 1.022640) 289.407
4 x calorific value (x 39.3) 11373.699
5 / kWh conversion factor (/3.6) 3159.361

* Only if your meter measures cubic feet rather than cubic metres. If you have a metric meter, you do not need to use the imperial to metric conversion factor (2.83). In this case, the rough estimate is to multiply the metric units by 11 instead of 31.3.

This is the approximately the same as: gas units used x 31.6 = kilowatt hours used, or, roughly, gas units x 100 divided by 3.

If you do not know whether you have a metric meter please see the Gas Meter Readings page which will help identify what kind of meter you have.

Back to top

What is a kilowatt-hour or kWh?

Every appliance you use in your home will have a power rating measured in kilowatts. The power rating tells you the number of kilowatts that the appliance uses when on full power. A kilowatt-hour (kWh) is the amount of kilowatts the appliance uses per hour. So, for example, if you have an appliance with a power rating of 1.8 kilowatts, and you use that appliance for one hour on full power, then you have used 1.8 kilowatt-hours of power for all the time it has been on.

Back to top

How much does it cost to run my appliance?

For those appliances that always run on max power and for which it is possible to measure how long they run for (such as a kettle or a toaster), simply multiply the power rating (given in the appliance manual in kilowatts) by the number of hours it runs for, by the price you pay for energy per kilowatt-hour. This can be done easily by using the Running Costs Calculator.

For some appliances it can be difficult to calculate how much they cost to run, either because it is hard to tell how many kilowatts the appliance uses, or to tell how long the appliance runs for.

A cooking hob, for example, might have a power rating of 1.8kW, meaning that it uses 1.8kW on full power; but this isn't helpful if you want to know how many kilowatts it uses when on it's lowest heat setting. A fridge turns itself on and off all day long, depending on how cold it is inside the fridge. Factors such as the temperature outside, the number of times it gets opened, the amount of food inside, can all affect how long it has to runs for.

The only definitive way to measure how much power such appliances use over time is to connect them to a power meter. Find out more about these energy monitors on our energy monitor page.

Back to top

Gas and Electricity Industry

What happened in the Gas and Electricity Markets?

In May 1998 the Government brought in new regulations to fully open the Gas market to competition. In May 1999, the same happened for Electricity. The increased competition in the market means that there are now many more opportunities for people to save money on their gas and electric bills. Since the new regulations were brought into place, over 7 million people have switched their gas and electricity supply, according to Ofgem. help energy users to compare prices for all suppliers in the UK, with only a few clicks. This can save hours of collecting each supplier's tariff data and making precise comparisons between the different pricing structures. More than this, our service is entirely free! All we ask is that you use the Switch links available on our website, as we are funded by a referral fee paid to us by the supplier. Using our service will make no difference to the price of your bills, and you won't find tariff prices cheaper anywhere else, even direct from the supplier.

Back to top

Who is OFGEM?

Ofgem is the OFfice of Gas and Electricity Markets, which was formed in June 1999. It promotes competition in the gas and electricity markets to ensure the consumers get genuine value and choice.

Ofgem took over the task of looking after consumers from Consumer Focus in 2013, which was the independent consumer organisation created through the merger of Energywatch with Postwatch and the Welsh, Scottish and National Consumer Councils protect the interests of gas and electricity consumers.

Ofgem is a good place to go for detailed energy supplier information, or if you need help dealing with your current energy supplier.

Visit the OFGEM website

Back to top

Energy Efficiency

Customers are urged to consider ways of saving energy. This not only helps to save you money but also helps the environment. There are various ways of doing this and many details can be found on the Energy Savings Trust website.

Visit the Energy Savings Trust website

Back to top

Northern Ireland Postcodes

Unfortunately, this service is currently only available for England, Scotland and Wales.

Back to top

Switching Gas and Electricity Supplier

Why would I want to change supplier?

As with anything else you buy, there are choices on prices and service available. By looking around you may be able to save money buying your electricity and/or gas from another supplier or simply just changing the tariff you are on.

Back to top

Is it easy to change?

Changing energy suppliers is easy to do. There are many different suppliers to select from. In choosing a new supplier you need to check their prices and this is where the price comparison service can help.

Back to top

How do I change suppliers?

  1. First, carry out a price comparison to see how your existing tariff compares. Use the Price Comparison Service by entering your postcode, existing suppliers, and amounts paid, to obtain a complete list of prices available in your region.
  2. Review the list and see how your existing suppliers compare with the others. You may find that either your current supplier or a different supplier has a cheaper tariff that you can switch to.
  3. When you are ready to switch, click the Switch button the easy application process on this site will guide you through the switching process.
  4. When you are ready to switch, use the application process on this site and we will help you through the switching process.
  5. When you arrive at the application form, complete all information requested and submit the form.
  6. At some stage your new supplier will ask you to provide meter readings which will be used by both suppliers to prepare final and opening bills.

Back to top

What information do I need to have in order to change supplier?

Apart from your name, address and contact details, you need to know the names of your existing suppliers (See "Who is my supplier?"). If you choose to pay by Direct Debit, you will also need to have your bank details to hand.

Back to top

Do I need to tell my existing supplier?

The official answer to this is Yes. However, in practice, the new transfer applications go through a process which includes checking with the existing supplier if there are any objections to the change. This is usually sufficient to act as notice that a change is being requested and arranged. It is best to telephone or write to the existing supplier and let them know, especially if you are coming to the end of a fixed term contract.

You may find that your current supplier may contact you to establish why you are leaving. Usually it’s due to price but occasionally there are other reasons and the suppliers like to establish the reason for leaving in order to help them with issues that customers may be unhappy with for the future.

The new supplier will send you a welcome letter explaining what will happen during the transfer process. When the transfer is about to take place the new supplier will ask you to take meter readings. They will then use those readings to “open” your account. They will also send them to your existing supplier who will use them to “close” your old account.

Generally speaking, the entire transfer process has been designed to operate as smoothly as possible and Ofgem keep an eye on the marketplace to ensure this happens.

Back to top

Transfers to your new supplier

Delivery of new services will be advised directly by your new supplier. Your new supplier will provide full details as well as their own Terms and Conditions which you should read carefully.

Transfers from one supplier to another can take between 4 to 6 weeks. The precise details will be advised by your new supplier.

Back to top

Just moved in to a new property?

To compare energy prices with, you will need to provide us with an estimated cost of your current usage and the name of your current suppliers. This is so that we can provide you with an accurate estimate of the savings available to you.

If for any reason you don't know your current usage, or if you have not lived at your property before and have no current usage, you will have the option to select 'I don't know'. When this is selected, we compare default the figures for an average sized house in the UK. These default figures are a good starting point and help you to identify which suppliers are cheapest in your area.

Back to top

Moving House

When you move in to a new property, you need to contact the existing suppliers and get the account changed in to your own name. If you need to find out who the existing suppliers are see "Who is my supplier?" above.

Once the accounts are in your name, you can start looking for a cheaper supplier by running your details through the Price Comparison Service. To do this, enter your postcode, and you will be asked for your current energy supply details. If you don't know who supplies your energy, use the default suppliers already selected, and select the 'I don't know' options for your usage amounts to see a full list of suppliers ranked in the order of price savings. At this stage you can click the 'Switch' button to begin the transfer process. Altogether, it can take between 6 to 8 for your gas and electric to be switched to the new supplier.

Back to top

If I submit my application, who does what next, and when?

Once you have submitted your application you will receive an automatically generated email confirming your switch, with the new supplier details. This should be checked carefully to ensure that all details have been entered correctly. This confirmation email will also contain your unique reference number in case you need to contact

We will submit your application to the supplier for the switch registration process to begin. You receive a welcome pack explaining what will happen during the transfer process. When the transfer is about to take place the new supplier will ask you to take meter readings, which they will then use to “open” your account. They will also send them to your existing supplier who will use them to “close” your old account.

If you currently pay by Direct Debit, do not cancel this arrangement until your existing supplier has taken the final Direct Debit. The whole process should take from between 4 to 6 weeks to be completed.

Back to top

What supplier or tariff would you recommend?

As an impartial, independent service we are not permitted to recommend any particular supplier, however, in general the cheapest deals include:

  • dual fuel (both electricity and gas from the same supplier)
  • online billing
  • Monthly Direct Debit payments

Back to top

When will the Direct Debit payments to my new supplier begin?

The new supplier will confirm your Direct Debit details to you, along with the amounts and the date the first payment will be taken from your bank account given on your application.

Back to top

Will I get Direct Debited by both old and new suppliers simultaneously?

No. Your new supplier will liaise with your current supplier and your bank during the switch over process to ensure that your new Direct Debit begins after your last Direct Debit payment to your current supplier.

Back to top

Do you need meter readings?

When the transfer is about to take place the new supplier will ask you to take meter readings. They will then use these readings to “open” your account and send them to your existing supplier who will use them to “close” your old account.

Back to top

When can I cancel my switch?

During the initial 7 to 14 day 'cooling-off' period please reply to our confirmation email (or contact us at to cancel or contact the new supplier directly after you have received your new welcome pack.

Back to top

When can I switch again if I'm unhappy with the new supplier?

You may have to be supplied by the new supplier for a minimum of 28 days. Fixed term or fixed price tariffs will specify the minimum period before you can leave without paying a penalty, if there is one. Be sure to check the Terms & Conditions of all tariffs for early departure fees.

Back to top

If I'm with first:utility and switch away, what will happen to my smart meter?

Your smart meter will stay where it is and can be made dumb - smart functionality can be switched on or off. Your new supplier will take it over. However, sometimes new suppliers choose to replace the meter, even when it has only recently been installed.

Back to top

What are the benefits of having a smart meter?

Smart meters transmit meter readings direct to the supplier for billing purposes, meaning the supplier doesn't have to visit your property to get meter readings. There two main benefits of smart meters are:

  • no-one has to come round to read your meter.
  • your bills will be accurate - no more estimated bills or over or under-paying.

Back to top

How does smart meters work?

A smart meter works by communicating directly with your energy supplier, so they will always have an accurate meter reading and there's no need for you to take a meter reading yourself. One way smart meters work is by an inbuilt SIM card like the one in your mobile phone to send the readings to the supplier.

Back to top

More FAQ's will be added as requested or required. We welcome and value your feedback and suggestions. Good comments help to improve our services. To contact us please email

Home gas and electricity price comparison

Found this page interesting?

Help spread the word and share this page with your friends and family on your social networks.