Retail Market Indicators

In our monitoring of the retail energy market for gas and electricity, we collect and analyse a vast range of data. Our retail market indicators give a snapshot of this monitoring. They draw from a comprehensive framework which underpins our ongoing monitoring, including our annual update on the retail energy markets in Great Britain. You can view these updates in the related publications section below. 

Our interactive retail market indicators

Select from the below to view the indicators in detail and for an overview of our monitoring themes.

If you have feedback on the indicators, please contact us.

Retail highlights April 2019

Prices and Profits

Increasing wholesale costs were a key driver in increasing the default tariff cap to £1254 on 1 April 2019.

As of 28 April 2019, the average price of SVTs from the six large suppliers for a typical dual fuel customer paying by direct debit was £1,254, as these suppliers increased their SVT prices towards the new default tariff cap level.

The market cheapest tariff decreased from £892 to £880 between 28 March 2019 and 28 April 2019. The differential between the average large six SVT price and the market cheapest tariff increased from £245 to £374. The differential relative to the basket of the ten cheapest tariffs also increased from £191 to £324.  

The prepayment price cap level also rose on 1 April 2019 to £1242 as a result of increasing wholesale costs. The weighted average SVT price among the eight largest prepayment suppliers increased to £1241, with the differential to the cheapest prepayment tariff increasing to £218.

See Prices and Profits.

Switching

Switching continues on an upward trend. The number of domestic switches in the 12 months up to March 2019 was 10% higher than in the 12 months up to February 2018 for electricity and 11% higher for gas. The number of switches in March 2019 was the highest ever recorded in the month of March.

See Switching and Consumer Experience.

Market structure

The number of active suppliers in the domestic retail market fell from 67 to 62 in Q4 2018. Five suppliers exited the market and no new suppliers entered in this period.

In Q4 2018, small and medium suppliers grew to a combined market share of 26% and 27% in electricity and gas, respectively.  The market share of the six large suppliers was down to 74% in electricity and 73% in gas.

Chart

Javascript is required to render chart Number of active domestic suppliers by fuel type (GB).

Source: Ofgem analysis of distribution network operator (DNO) and Xoserve reports.

Information correct as of: April 2019

This chart shows the number of active licensed suppliers in the domestic gas and electricity markets. It also gives a breakdown by those supplying both gas and electricity, and those who supply only one fuel. 

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Number of active domestic suppliers by fuel type (GB)
GasElectricity Gas and electricityTotal
Dec 2004101213
Dec 2005101112
Dec 200610910
Dec 2007101011
Dec2008101112
Dec 2009001212
Dec 2010001212
Dec 2011001414
Dec 2012221620
Dec 2013421824
Jun 2014222024
Sep 2014332127
Dec 2014322227
Mar 2015332329
Jun 2015332531
Sep 2015322833
Dec 2015533240
Mar 2016523643
Jun 2016513844
Sep 2016624048
Dec 2016634251
Mar 2017624553
Jun 2017744859
Sep 2017745465
Dec 2017755668
Mar 2018745970
Jun 2018726170
Sep 2018725867
Dec 2018725362

More information

At-a-glance summary

There were 62 active suppliers in the domestic gas and electricity retail markets as of December 2018. These consisted of the six large suppliers and 56 other suppliers, mainly active in both gas and electricity.

From October to December 2018 the number of active domestic suppliers continued to decline.  This was due to no new entry occurring during this period, as well as the exit of five suppliers. For more detail on market entries and exits see the new indicator ‘Supplier entries and exits in the domestic retail energy market’.

In May 2018, Co-operative Energy bought Flow Energy through direct corporate acquisition. Similarly, in September 2018, Octopus Energy acquired Affect Energy. We have recently confirmed that both Flow Energy and Affect Energy have been operating as fully owned, but separately licensed brands, of Co-operative Energy and Octopus Energy, respectively. Accordingly, we have stopped considering Flow Energy as a separate supplier from June 2018 and Affect Energy from September 2018.

Relevance and further information

The number of active suppliers in the GB energy market helps us to understand the dynamics of market concentration over time, as new participants enter; win customers and some existing firms exit the market.

Methodology

We calculate the number of active licensed suppliers (i.e. those with customers) from the information that both network operators and suppliers provide to us. White label suppliers are not included in this number. White label suppliers are organisations without supply licenses that partner with an active licensed supplier to offer gas and electricity using their own brand.

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Chart

Javascript is required to render chart Gas supply market shares by company: Domestic (GB) .

Source: Ofgem analysis of Xoserve reports.

Information correct as of: April 2019

This chart shows the domestic gas market shares for each of the six large suppliers, medium and small suppliers.

Chart tip: To look at a specific data series or to switch a series view on and off, click on a title in the chart legend (e.g. British Gas).

Policy Areas:

  • Gas - retail markets

Data Table

Gas supply market shares by company: Domestic (GB)
British GasEDFEONnpowerScottish PowerSSEUtility Warehouse OVO EnergyShell EnergyUtilitaCo-operative EnergyGreen Star EnergyBulbOctopus EnergySmall Suppliers
2005 Q255%5%12%10%9%9%
2005 Q355%5%12%10%9%10%
2005 Q454%5%12%10%9%10%
2006 Q154%5%12%10%9%10%
2006 Q252%6%12%11%9%11%
2006 Q351%6%12%11%8%11%
2006 Q450%6%12%12%8%12%
2007 Q148%7%12%12%9%13%
2007 Q248%7%12%12%8%13%
2007 Q348%7%12%12%8%14%
2007 Q447%7%11%12%8%14%
2008 Q147%7%12%12%8%14%
2008 Q246%7%12%12%8%15%
2008 Q345%7%12%12%9%15%
2008 Q445%7%12%12%9%16%
2009 Q144%7%12%12%9%16%
2009 Q244%7%12%12%9%16%
2009 Q344%7%12%12%8%16%
2009 Q444%7%12%12%8%16%
2010 Q144%7%12%12%8%16%
2010 Q244%7%12%12%8%16%
2010 Q344%7%12%11%8%16%
2010 Q443%7%12%11%9%16%
2011 Q143%8%13%11%9%16%
2011 Q243%7%13%11%9%16%
2011 Q343%8%13%12%8%16%
2011 Q442%8%13%12%8%16%
2012 Q142%8%13%12%8%16%0%0%0%0%0%0%
2012 Q242%8%13%12%8%16%0%0%0%0%0%0%
2012 Q341%9%13%12%9%15%0%0%0%0%0%0%
2012 Q441%9%13%12%9%15%0%0%1%0%0%0%
2013 Q141%8%13%12%9%15%0%0%1%0%0%0%0%
2013 Q241%9%13%11%9%15%0%0%1%0%0%0%0%
2013 Q340%9%13%11%9%15%0%0%1%0%1%0%1%
2013 Q439%9%13%10%9%15%2%0%1%0%1%0%1%
2014 Q139%9%12%10%9%14%2%1%2%0%1%0%1%
2014 Q238%9%12%10%9%14%2%1%2%0%1%0%1%
2014 Q338%9%12%10%9%14%2%1%2%1%1%0%1%
2014 Q438%9%12%9%9%14%2%1%3%1%1%0%1%
2015 Q138%9%12%9%9%13%2%2%3%1%1%0%1%
2015 Q237%9%12%9%9%13%2%2%3%1%1%0%2%
2015 Q337%8%12%9%9%13%2%2%3%1%1%0%0%2%
2015 Q437%8%12%9%9%13%2%2%4%1%1%0%0%2%
2016 Q136%8%11%9%9%13%2%2%4%1%1%0%0%0%3%
2016 Q236%8%11%9%9%12%2%3%4%2%1%1%0%0%4%
2016 Q335%8%11%9%9%12%2%3%4%2%1%1%0%0%4%
2016 Q435%8%10%9%9%12%2%3%4%2%1%1%0%0%5%
2017 Q134%8%10%8%9%12%2%3%3%2%2%1%0%0%6%
2017 Q233%8%11%8%9%11%2%2%3%2%1%1%0%0%7%
2017 Q332%9%11%8%9%11%2%3%3%2%1%1%1%0%8%
2017 Q431%9%11%8%9%11%2%3%3%2%1%1%1%0%9%
2018 Q130%8%11%8%9%11%2%3%3%2%1%1%1%1%8%
2018 Q230%8%11%8%8%11%2%3%3%2%1%1%2%1%9%
2018 Q329%8%11%7%8%10%2%3%3%2%1%1%3%1%9%
2018 Q429%8%11%7%9%10%2%4%3%2%1%1%3%2%9%

More information

At-a-glance summary

Between Q2 2011 and Q4 2018, the gas market share of the six large suppliers dropped from nearly 100% to 73%. The market share for the largest gas supplier in the GB domestic market, British Gas, fell from 43% to 29%. The market share held by medium and small suppliers was 27% in Q4 2018.

Relevance and further information

The evolution of market shares is a useful measure of trends in market concentration. They help us understand the impact between market shares and competitive dynamics, both for the six large suppliers and other suppliers, and which companies are winning or losing customers.

Methodology

We calculate market shares from the number of meter points on the gas distribution networks, as provided to us by Xoserve. As of July 2017, supply points connected to independent gas transporters are included in the gas data provided by Xoserve.

We periodically review, typically with a lag of one quarter, the group of suppliers that we define as medium and small.

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Chart

Javascript is required to render chart Electricity supply market shares by company: Domestic (GB) .

Source: Ofgem analysis of electricity distribution network operator reports.

Information correct as of: April 2019

This chart shows the domestic electricity market shares for each of the six large suppliers, medium and small suppliers.

Chart tip: To look at a specific data series or to switch a series view on and off, click on a title in the chart legend (e.g. British Gas).

Policy Areas:

  • Electricity - retail markets

Data Table

Electricity supply market shares by company: Domestic (GB)
British GasEDFE.ONnpowerScottish PowerSSECo-operative EnergyShell EnergyOVO EnergyUtilitaUtility WarehouseGreen Star EnergyBulbOctopus EnergySmall Suppliers
Q1 200424%14%21%15%11%14%0%
Q2 200424%14%21%15%12%15%0%
Q3 200424%14%21%15%12%15%0%
Q4 200423%13%21%15%13%15%0%
Q1 200522%13%21%15%13%15%0%
Q2 200522%13%21%15%13%16%0%
Q3 200522%13%20%15%13%16%0%
Q4 200522%13%20%15%13%16%0%
Q1 200622%13%20%15%13%16%0%
Q2 200622%14%20%15%13%16%0%
Q3 200622%14%20%15%12%17%0%
Q4 200622%14%19%16%12%17%0%
Q1 200722%14%19%16%12%18%0%
Q2 200722%14%19%16%12%18%0%
Q3 200722%13%18%16%12%18%0%
Q4 200722%13%18%15%12%18%0%
Q1 200822%13%18%15%12%19%0%
Q2 200822%13%18%15%12%19%0%
Q3 200822%13%18%15%12%19%0%
Q4 200822%13%18%15%12%19%0%
Q1 200922%13%18%15%12%20%0%
Q2 200923%13%18%15%12%20%0%
Q3 200923%13%18%15%12%20%0%
Q4 200923%13%18%14%12%20%0%
Q1 201024%13%17%14%12%20%1%
Q2 201024%13%17%14%12%20%1%
Q3 201024%13%17%14%12%20%1%
Q4 201025%13%17%14%11%20%1%
Q1 201125%13%17%14%11%20%1%
Q2 201125%13%17%14%11%20%1%
Q3 201125%13%17%14%11%19%1%
Q4 201125%13%17%14%11%19%1%
Q1 201225%13%17%14%11%19%1%
Q2 201225%13%17%14%11%19%1%
Q3 201225%13%17%14%11%19%1%
Q4 201225%13%17%14%12%18%0%1%0%0%0%0%
Q1 201325%13%17%13%12%18%0%1%1%0%0%0%1%
Q2 201325%13%17%13%12%18%0%1%1%0%0%0%1%
Q3 201325%13%16%13%12%18%0%1%0%0%0%0%1%
Q4 201324%13%16%12%12%18%1%1%0%0%1%0%1%
Q1 201424%13%16%12%12%17%1%1%1%0%2%0%1%
Q2 201424%13%16%12%11%17%1%2%1%0%2%0%1%
Q3 201424%13%16%11%11%17%1%2%1%0%2%0%2%
Q4 201424%13%16%11%11%17%1%3%1%1%2%0%2%
Q1 201524%13%16%11%11%16%1%3%2%1%2%0%2%
Q2 201524%12%16%11%11%16%1%3%2%1%2%0%2%
Q3 201524%12%16%11%11%16%1%3%2%1%2%0%0%3%
Q4 201523%12%15%10%11%16%1%3%2%1%2%0%0%0%3%
Q1 201623%12%15%10%11%15%1%3%2%1%2%0%0%0%4%
Q2 201623%12%15%10%11%15%1%3%2%1%2%0%0%0%4%
Q3 201623%12%14%10%11%15%1%3%2%1%2%0%0%0%5%
Q4 201623%12%14%10%11%15%1%3%2%2%2%0%0%0%5%
Q1 201722%12%14%9%11%15%2%3%2%2%2%1%0%0%6%
Q2 201722%12%13%10%11%14%1%3%2%2%2%1%0%0%7%
Q3 201721%12%13%10%10%14%1%3%3%2%2%1%0%0%8%
Q4 201720%11%13%10%10%14%1%3%3%2%2%1%1%0%9%
Q1 201820%11%13%9%10%14%1%3%3%2%2%1%1%1%8%
Q2 201820%11%13%9%10%14%1%3%3%2%2%1%2%1%8%
Q3 201819%11%13%9%10%13%1%3%4%2%2%1%3%1%8%
Q4 201819%11%13%8%10%13%1%3%4%2%2%1%3%2%8%

More information

At-a-glance summary

Between Q2 2011 and Q4 2018, the combined electricity market share of the large six suppliers dropped from nearly 100% to 74%. The market share held by medium and small suppliers was 26% in Q4 2018.

Relevance and further information

The evolution of market shares is a useful measure of trends in market concentration. They help us understand the impact between market shares and competitive dynamics, both for the six large suppliers and other suppliers, and which companies are winning or losing customers.

Methodology

We calculate market shares from the number of meter points on the electricity distribution networks, as provided to us by electricity distribution network operators.

We periodically review, typically with a lag of one quarter, the group of suppliers that we define as medium and small.

close

Chart

This chart shows the number of licenced suppliers that have started or stopped actively supplying customers in the GB domestic gas and electricity markets in each quarter in comparison to the total number of suppliers that continued to supply the market in the same period.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Supplier entries and exits in the domestic energy retail market (GB)
Supplier entriesSupplier exitsContinuing active suppliers
2016 Q13040
2016 Q21043
2016 Q34044
2016 Q45-246
2017 Q12051
2017 Q26053
2017 Q37-158
2017 Q43065
2018 Q13-167
2018 Q21-169
2018 Q30-367
2018 Q40-562

More information

At-a-glance-summary

There has been a steady increase in the number of suppliers becoming active in the domestic energy markets up to mid-2018. In the second half of 2018, no new domestic suppliers have become active, while 8 suppliers left the market.

Between July 2018 and December 2018, there were seven exits for which we had to appoint a Supplier of Last Resort (SoLR) to absorb their customers: Iresa, GEN4U, Usio, Snowdrop Energy, Spark Energy, Extra Energy, OneSelect. Another exit occurred in September 2018, when Octopus directly acquired Affect Energy, which has since been operating as a separately licensed brand, fully owned by Octopus.

Between January 2019 and March 2019, three suppliers exited the market through the SoLR process. These suppliers were: Economy Energy, Our Power, Brilliant Energy. These exits will be shown in this chart in future quarterly updates to the indicators.

Relevance and further information

This chart helps understand the GB energy market dynamics by showing the number of entries and exits that underpins the evolution in the number of active licensed suppliers over time.

For a breakdown of how many active suppliers are supplying each fuel type please go to our chart Number of active suppliers by fuel type.

Methodology

We calculate the number of entries, exits and total number of active licensed suppliers (i.e. those with customers) from the information that both network operators and suppliers provide to us. White label suppliers are not included in this number. White label suppliers are organisations without supply licenses that partner with an active licensed supplier to offer gas and electricity using their own brand.

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Prices and profits

Increasing wholesale costs were a key driver in increasing the default tariff cap to £1254 on 1 April 2019.

As of 28 April 2019, the average price of SVTs from the six large suppliers for a typical dual fuel customer paying by direct debit was £1,254, as these suppliers increased their SVT prices towards the new default tariff cap level.

The market cheapest tariff decreased from £892 to £880 between 28 March 2019 and 28 April 2019. The differential between the average large six SVT price and the market cheapest tariff increased from £245 to £374. The differential relative to the basket of the ten cheapest tariffs also increased from £191 to £324.  

The prepayment price cap level also rose on 1 April 2019 to £1242 as a result of increasing wholesale costs. The weighted average SVT price among the eight largest prepayment suppliers increased to £1241, with the differential to the cheapest prepayment tariff increasing to £218.

Excluding prepayment customers, the proportion of domestic customer accounts on default tariffs among twelve of the thirteen large and medium suppliers was 52% in electricity and 50% in gas as of 1st January 2019. Including prepayment customers, this proportion was 58% for electricity and 56% for gas.

Chart

Source: Energylinx (Until May 2017) & Energyhelpline (June 2017 onwards).

Information correct as of: May 2019

This chart shows trends in domestic energy bills by tariff offered by the six large suppliers and other suppliers. It compares their average standard variable tariffs with the cheapest tariffs available in the market (including white label tariffs). Figures are based on a typical domestic dual fuel customer paying by direct debit. 

From February 2017 the prices shown in the chart are calculated using the latest Typical Domestic Consumption Values (TDCV) that entered into effect from 1st of October 2017 (see the methodology section for more details).

In practical terms, this means that the tariffs offered after February 2017 are likely to appear slightly lower than those before February 2017.  

This information should not be used as a price comparison tool. To find out about accredited price comparison sites, see Compare gas and electricity tariffs.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Retail price comparison by company and tariff type: Domestic (GB)
DateAverage standard variable tariff (Six large suppliers)Average standard variable tariff (Other suppliers)Cheapest tariff (Six large suppliers)Cheapest tariff (All suppliers)Cheapest tariff (Basket)Default tariff cap level
28/01/20121020.161024.33915.27906.56947.56
28/02/20121000.761017.41886.18878.10930.29
28/03/2012997.251017.41886.18878.10936.54
28/04/2012997.251017.35895.69878.10937.68
28/05/2012997.251017.35895.69878.10929.78
28/06/2012997.251032.16895.69895.69945.53
28/07/2012997.251032.16895.69875.93928.99
28/08/2012997.251030.02899.10875.93924.85
28/09/2012997.251017.84901.47875.93931.04
28/10/20121009.001020.51906.17893.85956.00
28/11/20121030.781075.12958.21909.59997.71
28/12/20121061.801087.65990.70909.59994.59
28/01/20131074.421087.65957.18909.59990.81
28/02/20131074.421119.05957.18909.59994.56
28/03/20131074.421119.05966.54909.59995.50
28/04/20131074.421119.05966.54909.59988.37
28/05/20131074.431119.05966.54962.43997.77
28/06/20131074.431119.05966.54769.95967.26
28/07/20131074.451119.05984.68769.95974.82
28/08/20131074.451119.05971.77769.95988.47
28/09/20131074.451119.05971.77769.95979.55
28/10/20131074.451127.021011.80769.95995.67
28/11/20131105.941123.75993.40769.95992.26
28/12/20131138.951123.751033.47769.95997.00
28/01/20141145.841125.141033.47975.211013.73
28/02/20141134.091128.761033.97966.341014.19
28/03/20141128.101126.611024.79964.311016.25
28/04/20141128.101129.621000.38946.42995.26
28/05/20141128.101129.621000.38944.55995.13
28/06/20141128.101129.621000.38944.55992.88
28/07/20141128.101134.191000.38944.95976.39
28/08/20141128.101127.791000.38943.43978.98
28/09/20141128.101158.39960.90942.27972.34
28/10/20141128.101131.80953.40931.02960.15
28/11/20141128.101131.80921.88914.51947.94
28/12/20141128.101130.51916.21906.14929.69
28/01/20151124.331130.51875.40871.26895.39
28/02/20151106.651110.84839.28839.28881.39
28/03/20151106.651088.31836.99836.99892.38
28/04/20151106.651075.32834.57834.57878.56
28/05/20151102.281073.26835.19830.56877.12
28/06/20151102.281073.26835.71830.56871.21
28/07/20151102.281066.77863.85830.56867.88
28/08/20151098.031066.77876.03830.56868.79
28/09/20151098.031054.98876.03830.56858.62
28/10/20151098.031050.12803.00793.93823.00
28/11/20151098.031040.70805.40787.05810.84
28/12/20151098.031039.03850.52787.05803.86
28/01/20161098.031035.48769.69765.00785.04
28/02/20161092.691020.06738.38738.38755.65
28/03/20161071.441013.00727.70727.70756.05
28/04/20161065.97978.55723.91723.91751.58
28/05/20161065.97976.04723.23723.23742.71
28/06/20161065.97984.02723.23723.23751.36
28/07/20161065.97988.70779.39758.31779.72
28/08/20161065.97983.86801.37769.65789.25
28/09/20161065.97983.89754.64744.30777.00
28/10/20161065.97994.93803.54741.92786.41
28/11/20161065.971012.84897.18790.02859.23
28/12/20161065.971019.72951.51790.02872.16
28/01/20171061.061020.10951.51833.71881.11
28/02/20171081.271027.06928.48829.10869.79
28/03/20171109.481035.47922.23829.10873.38
28/04/20171122.281041.56923.55863.31874.62
28/05/20171122.281039.22923.57826.52861.76
28/06/20171122.281026.98923.57835.76852.58
28/07/20171122.281030.63922.82829.91844.94
28/08/20171122.281030.76910.05810.11839.30
28/09/20171134.951026.42904.48826.73837.66
28/10/20171134.951031.41897.98826.73854.69
28/11/20171134.951044.84928.59826.73846.77
28/12/20171134.951040.86973.04798.72841.48
28/01/20181134.951036.14907.89809.32840.81
28/02/20181134.951039.85900.98810.06840.58
28/03/20181134.951044.29900.98810.11842.91
28/04/20181138.281061.811000.42788.16820.46
28/05/20181138.281060.56962.53788.16832.69
28/06/20181172.201066.39953.16796.99845.91
28/07/20181184.791075.35965.27826.73861.22
28/08/20181194.001091.02951.33842.49897.02
28/09/20181205.621104.911043.21920.60982.09
28/10/20181220.651124.271051.27920.60989.84
28/11/20181220.651140.971030.12946.13993.80
28/12/20181220.651142.961034.69902.66983.19
28/01/20191136.671099.491035.63941.26992.851137.47
28/02/20191136.671097.671008.69929.66974.581137.47
28/03/20191136.671094.871011.22891.94945.991137.47
28/04/20191253.941152.111024.59880.20929.551254.00
28/05/20191254.00

More information

At-a-glance summary

As of April 2019, the average price of SVTs for the six large suppliers for a typical dual fuel customer paying with direct debit was £1,254, an increase from £1,137 in the previous month as suppliers have increased the prices of their SVTs to the new level of the default tariff cap.

The cheapest tariff in the market in April 2019 was £880. This was £12 cheaper than the cheapest tariff in the previous month. However, it is £92 more expensive than the cheapest tariff in April 2018. The cheapest tariff basket was £930 in April 2019, £16 cheaper than in March 2019. See the methodology for information on how the cheapest tariff basket is calculated.

The differential between the average price of SVTs for the six large suppliers and the market cheapest tariff increased from £207 to £374 between March and April 2019, while the differential to the cheapest tariff basket increased from £191 to £324. This was mostly as a result of the increase in the price of SVTs.

For details on prices of fixed default tariffs, please see the chart showing Average tariff prices per supplier.

Relevance and further information

Tariff differentials reflect pricing in different market segments, as well as how much other suppliers are able to compete on price with the six large suppliers.

Methodology

We calculate the bill values associated with the different tariff types using a ‘typical medium domestic consumer’. As of October 2017, typical domestic consumption values (TDCV) for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1). The chart includes collective switching tariffs from Q1 2016. All tariffs shown in the chart are for a dual fuel, direct debit customer. Dual fuel refers to a situation where a customer takes gas and electricity from the same supplier.

A standard variable tariff refers to a supply contract which is for a period of an indefinite length and which does not contain a fixed term period that applies to any of the terms and conditions. It’s an energy supplier’s basic offer. If a customer does not choose a specific energy plan, for example after their fixed tariff ends, they will be moved on a standard variable tariff until they have chosen a new one. A customer can also make an active choice to select a standard variable tariff.

Tariffs with limited availability depending on customer features (for example, tariffs which are only available to new customers, also known as ‘acquisition’ tariffs, or tariffs restricted to certain regions) are excluded from the calculation to make sure that all tariffs considered are generally available to all customers across GB.

Tariffs available with white label suppliers are included in the calculation of the cheapest tariffs. White label suppliers are organisations without supply licences that partner with an active licensed supplier to offer gas and electricity using their own brand.

To calculate the average of the cheapest tariffs from the 10 cheapest suppliers we took the cheapest tariff offered by each supplier in the market (i.e. one tariff per supplier) and then ranked the tariffs in order of price. We then took the simple average of the 10 cheapest tariffs in this list. This method is to ensure a cross section of suppliers is included in the calculation.

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Chart

Source: Energylinx (Until May 2017) & Energyhelpline (June 2017 onwards).

Information correct as of: May 2019

This chart compares the cheapest available tariffs offered by the six large suppliers with the cheapest tariff available in the market by payment method (direct debit, standard credit and prepayment). Figures are based on a typical domestic dual fuel customer.

From February 2017 the prices shown in the chart are calculated using the latest Typical Domestic Consumption Values (TDCV) that entered into effect from 1st of October 2017 (see the methodology section for more details).

In practical terms, this means that the tariffs offered after February 2017 are likely to appear slightly lower than those before February 2017.  

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Cheapest tariffs by payment method: Typical domestic dual fuel customer (GB)
DateLarge six suppliers (direct debit)Large six suppliers (standard credit)Large six suppliers (prepayment)Market (direct debit)Market (standard credit)Market (prepayment)
28/01/2012915.27976.701021.54906.56971.04969.61
28/02/2012886.18976.701021.54878.10971.04969.61
28/03/2012886.18976.701021.54878.10971.04969.61
28/04/2012895.69953.401021.54878.10953.40969.24
28/05/2012895.69953.401021.54878.10890.12969.24
28/06/2012895.69953.401021.54895.69953.401017.42
28/07/2012895.69953.401021.54875.93953.401017.42
28/08/2012899.10957.031021.54875.93957.031017.42
28/09/2012901.471020.711021.54875.93988.141017.42
28/10/2012906.171020.711069.39893.85988.141019.30
28/11/2012958.211020.711069.39909.59979.351045.64
28/12/2012990.701071.381133.19909.59979.351045.64
28/01/2013957.181037.201133.19909.59979.351045.64
28/02/2013957.181037.201133.19909.591037.201045.64
28/03/2013966.541046.571133.19909.591046.571045.64
28/04/2013966.541046.571133.19909.591046.571045.64
28/05/2013966.541046.571133.19962.43996.901045.64
28/06/2013966.541046.571133.19769.95996.901045.64
28/07/2013984.681075.511133.19769.95996.901045.64
28/08/2013971.771051.791133.19769.951051.791045.64
28/09/2013971.771051.791133.19769.951051.791045.64
28/10/20131011.801079.911133.19769.951070.991093.35
28/11/2013993.401058.151150.97769.951058.151093.35
28/12/20131033.471101.651178.61769.951101.651093.35
28/01/20141033.471101.651178.61975.211101.651172.77
28/02/20141033.971108.101178.61966.341108.101172.77
28/03/20141024.791117.271178.61964.311117.271171.39
28/04/20141000.381069.951178.61946.421069.951171.39
28/05/20141000.381069.951178.61944.551069.951171.39
28/06/20141000.381069.951170.86944.551069.951162.40
28/07/20141000.381069.951170.86944.951029.051162.40
28/08/20141000.381069.951170.86943.431038.881154.43
28/09/2014960.901030.951170.86942.271030.951154.43
28/10/2014953.401046.451170.86931.021024.451154.43
28/11/2014921.881003.791170.86914.511003.791154.43
28/12/2014916.211003.791170.86906.141003.791151.22
28/01/2015875.40945.461148.99871.26945.461148.99
28/02/2015839.28955.071148.90839.28950.351148.90
28/03/2015836.99907.241148.99836.99907.241116.99
28/04/2015834.57977.561141.64834.57950.631116.99
28/05/2015835.19905.441141.64830.56905.441116.99
28/06/2015835.71981.781122.97830.56940.901116.99
28/07/2015863.85981.781122.97830.56939.851116.99
28/08/2015876.03977.321128.54830.56940.271116.99
28/09/2015876.03963.771128.54830.56907.261100.94
28/10/2015803.00873.251128.54793.93844.041100.94
28/11/2015805.40950.751128.54787.05844.041055.61
28/12/2015850.52950.751102.20787.05844.041055.61
28/01/2016769.69839.941102.20765.00839.941055.61
28/02/2016738.38808.631092.26738.38808.631054.20
28/03/2016727.70797.761070.37727.70797.761051.22
28/04/2016723.91793.481070.37723.91793.481030.27
28/05/2016723.23877.121037.31723.23877.121017.61
28/06/2016723.23847.451037.31723.23847.45985.97
28/07/2016779.39904.971037.31758.31871.54985.97
28/08/2016801.37941.421043.54769.65871.54985.97
28/09/2016754.64839.151043.54744.30839.15985.97
28/10/2016803.54967.131043.54741.92829.42985.97
28/11/2016897.181002.631035.64790.02907.75985.97
28/12/2016951.511031.571035.64790.02923.48985.97
28/01/2017951.511031.571035.64833.71951.58985.97
28/02/2017928.481033.401015.43829.10935.19970.67
28/03/2017922.231016.741019.21829.10949.48970.67
28/04/2017923.551018.06994.53863.31946.43970.67
28/05/2017923.571018.08994.53826.52923.47979.27
28/06/2017923.571018.08994.53835.76923.23979.27
28/07/2017922.821017.33994.53829.91923.23979.27
28/08/2017910.051004.56988.90810.11923.47979.27
28/09/2017904.481051.43988.90826.73923.47979.27
28/10/2017897.981012.47988.90826.73943.35978.04
28/11/2017928.591100.89988.90826.73958.08978.04
28/12/2017973.041051.43988.90798.72958.08957.12
28/01/2018907.891051.43988.90809.32958.08960.06
28/02/2018900.981050.871028.21810.06958.08945.76
28/03/2018900.981074.651028.21810.11958.08945.76
28/04/20181000.421143.141030.55788.16958.08946.63
28/05/2018962.531057.041030.93788.16958.08946.63
28/06/2018953.161033.191070.34796.99958.08946.63
28/07/2018965.271045.291070.34826.73990.66946.63
28/08/2018951.331198.371070.50842.49990.68946.54
28/09/20181043.211138.841070.50920.601067.64983.86
28/10/20181051.271164.581070.50920.601107.76983.86
28/11/20181030.121055.761115.66946.131055.76983.86
28/12/20181034.691134.341115.66902.661109.27983.86
28/01/20191035.631125.841115.66941.26941.261016.48
28/02/20191008.691040.001115.66929.661040.001023.39
28/03/20191011.221040.001115.66891.941040.001023.39
28/04/20191024.591228.881115.66880.201098.831023.39

More information

At-a-glance summary

Direct debit customers have traditionally been offered the cheapest tariffs, followed by standard credit customers and those using prepayment meters.  

After the introduction of the prepayment safeguard tariff in April 2017, the overall cheapest tariffs have continued to be those for direct debit customers. However, the ranking between standard credit and prepayment cheapest tariffs has fluctuated over time. Looking at the whole market, since February 2018 the cheapest prepayment tariff has been less expensive than the cheapest standard credit tariff. Among the six large suppliers, the cheapest prepayment tariff has been consistently less expensive than the cheapest standard credit tariff since April 2017, with the exception of June, July and November 2018 when the cheapest prepayment tariff was more expensive.

At the end of April 2019, the cheapest direct debit tariff in the market was £219 less expensive than the cheapest standard credit tariff and £143 less than the cheapest prepayment tariff. The cheapest direct debit tariff has historically been at least £100 less expensive than the cheapest standard credit tariff.

A prepayment price cap was introduced on 1 April 2017, limiting the amount that suppliers can charge their prepayment customers. The default tariff price cap came into effect on 1 January 2019, limiting the amount that suppliers can charge customers on default tariffs.

Relevance and further information

This indicator helps us understand pricing by payment methods, as well as how much other suppliers are able to compete with the six large suppliers for each method.

Methodology

We calculate the bill values associated with the different tariff types using a ‘typical medium domestic consumer’. As of October 2017, typical domestic consumption values (TDCV) for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1). The chart includes collective switching tariffs from Q1 2016.

All tariffs shown in the chart are for a dual fuel customer. Dual fuel refers to a situation where a customer takes gas and electricity from the same supplier.

Tariffs with limited availability depending on customer features (for example, tariffs which are only available to new customers, also known as ‘acquisition’ tariffs, or tariffs restricted to certain regions) are excluded from the calculation to make sure that all tariffs considered are generally available to all customers across GB.

Tariffs available with white label suppliers are included in the calculation of the cheapest tariff. White label suppliers are organisations without supply licences that partner with an active licensed supplier to offer gas and electricity using their own brand.

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Chart

Source: Energyhelpline; Suppliers.

Information correct as of: April 2019

This chart shows average prices in the last quarter for each of the 13 larger suppliers in the non-prepayment segment. These include suppliers’ default tariffs (SVTs and, if available, fixed term default tariffs) and cheapest tariffs, which are compared with the average price of the market cheapest tariff in the period between January and March 2019.

In this period, Bulb was offering only one tariff.

 

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Average tariff prices by supplier: Standard variable and fixed default vs cheapest available tariffs (GB)
SupplierSupplier's annual average fixed term default tariffSupplier's average annual standard variable tariffSupplier's cheapest annual average tariffMarket cheapest annual average tariffDefault tariff cap
British Gas1133113511339351137
SSE113711289351137
E.ON113710979351137
EDF113611179351137
Scottish Power113710799351137
npower1137113710319351137
Shell Energy113710249351137
OVO Energy113711109351137
Utility Warehouse113110579351137
Co-operative Energy113611229351137
Bulb101810189351137
Green Star Energy113711379351137
Octopus Energy106010109351137

More information

At-a-glance summary

In Q1 2019, the average standard variable tariff (‘SVT’) price for a domestic customer with one of the thirteen larger suppliers in the non-price protected segment ranged between £1,018 and £1,137. This period coincided with the implementation of the default tariff cap. The average SVT prices of eleven of the thirteen suppliers were within £6 of the cap level, set at £1,137 in this period.

In this period, British Gas and npower offered a fixed term default tariff. These were priced at a similar level to their SVTs.

The average cheapest deals in this period were all above the average market cheapest tariff of £935, ranging between £1,010 and £1,137. The average SVT price differentials in the period were between £0 and £113 relative to these suppliers' cheapest tariffs. The SVT price differentials were between £83 and £202 relative to the market cheapest tariff.

For an overview of the SVT and price trends over time see our chart on the Retail price comparison by company and tariff type.

Relevance and further information

This chart measures the savings available to customers on default tariffs if they change tariff or switch supplier.

It should be considered jointly with our charts on the Number of domestic gas customer accounts by supplier (excluding prepayment customers): Standard variable, fixed and other tariffs (GB) and the Number of domestic electricity customer accounts by supplier (excluding prepayment customers): Standard variable, fixed and other tariffs (GB)

Our data shows default tariffs are usually more expensive than other deals available in the market. Customers on default tariffs are potentially missing out on significant savings on their bills compared to cheaper tariffs from their existing or another supplier.

For previous updates, please see our page here.

Methodology

  • We calculate the bill values associated with the different tariff types using a ‘typical medium domestic consumer’. As of October 2017, typical consumption values for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1). All tariffs shown in the chart are for a dual fuel, direct debit customer. 
  • We use weekly prices across the quarter prior to publication to calculate the average SVT price. We take the price data for each Monday of every week in the analysed period. The source is Energyhelpline for SVT and cheapest tariffs, while fixed term default tariffs are sourced from suppliers. SVT prices in this chart always refer to paper billing prices. 
  • We use the same calculations to produce the average cheapest tariff price for each supplier and for the average market cheapest tariff price. When calculating the cheapest tariff at both individual supplier and market level, we exclude tariffs restricted to certain regions. This is so we give a representative picture of tariffs generally available to all customers across GB. 
  • When calculating the cheapest tariff at individual supplier level, we include tariffs only available to existing customers (also known as ‘retention' tariffs) and exclude tariffs only available to new customers (also known as ‘acquisition’ tariffs). 
  • When calculating the cheapest tariff at market level, we include tariffs only available to new customers (also known as ‘acquisition’ tariffs) and exclude tariffs only available to existing customers (also known as ‘retention' tariffs). 
  • Collective tariffs or exclusive deals only available through a supplier’s website or through a specific price comparison website are included to the extent they are ‘open collective switches’ available to all customers. We also include tariffs restricted to a particular payment method, except for prepayment. 
  • The cheapest tariffs can include fixed and variable tariffs, may or may not involve exit fees, rewards or discounts, may only be available online and may be offered by any suppliers active in the market. Some suppliers included in the average market cheapest tariffs may not offer the Warm Home Discount. 
  • We include tariffs available with ‘white label’ providers in the calculation of the market cheapest tariff. Where relevant, we have also included them in the cheapest tariff offered by the parent supplier of the ‘white label’. ‘White label’ providers are organisations without supply licences that partner with an active licensed supplier to offer gas and electricity tariffs using their own brand.
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Javascript is required to render chart Prepayment price cap and prices since January 2016 (GB).

Source: Energylinx (Until May 2017) & Energyhelpline (June 2017 onwards).

Information correct as of: May 2019

This chart compares trends in prices since 2016 for a dual fuel customer paying prepayment. It shows both the market cheapest tariffs and average standard variable tariffs (SVT) for this payment method. The values are calculated for a customer with typical energy use.

From February 2017 the prices shown in the chart, including the level of the prepayment price cap, are calculated using the latest TDCV values that entered into effect from 1st of October 2017 (see the methodology section for more details).

In practical terms, this means that the tariffs offered after February 2017 are likely to appear slightly lower than those before February 2017.  

Policy Areas:

  • Electricity - retail markets
  • Electricity - wholesale markets
  • Gas - retail markets
  • Gas - wholesale markets

Data Table

Prepayment price cap and prices since January 2016 (GB)
DateSVT - prepayment (market average)Cheapest tariff - prepayment (all suppliers)Prepayment price cap
28/12/20151163.441055.61
28/01/20161163.181055.61
28/02/20161158.611054.20
28/03/20161138.391051.22
28/04/20161131.321030.27
28/05/20161131.321017.61
28/06/20161131.32985.97
28/07/20161130.22985.97
28/08/20161130.22985.97
28/09/20161130.22985.97
28/10/20161130.22985.97
28/11/20161122.72985.97
28/12/20161122.72985.97
28/01/20171115.77985.97
28/02/20171061.14970.67
28/03/20171059.99970.67
28/04/20171032.30970.671050.35
28/05/20171032.30979.271050.35
28/06/20171032.30979.271050.35
28/07/20171032.69979.271050.35
28/08/20171031.31979.271050.35
28/09/20171034.46979.271050.35
28/10/20171030.60978.041031.27
28/11/20171030.60978.041031.27
28/12/20171030.60957.121031.27
28/01/20181030.72960.061031.27
28/02/20181030.72945.761031.27
28/03/20181030.85945.761031.27
28/04/20181079.09946.631088.55
28/05/20181086.20946.631088.55
28/06/20181086.19946.631088.55
28/07/20181086.08946.631088.55
28/08/20181086.06946.541088.55
28/09/20181086.06983.861088.55
28/10/20181135.42983.861135.99
28/11/20181135.42983.861135.99
28/12/20181135.42983.861135.99
28/01/20191135.231016.481135.99
28/02/20191135.231023.391135.99
28/03/20191135.231023.391135.99
28/04/20191241.441023.391242.07
28/05/20191242.07

More information

At-a-glance summary

In April 2017, the prepayment price cap came into force, limiting the amount that suppliers can charge their prepayment customers. These customers tend to be unable to access the cheapest deals and are also more likely to be in vulnerable circumstances.

The cheapest prepayment tariffs available in the market have remained below the average SVT for a prepayment customer following the introduction of the prepayment price cap. This differential between the average SVT and the cheapest prepayment tariff has remained over £100 since April 2018. In April 2019, this differential increased to £218 as suppliers increased the prices of their SVTs following the increase in the level of the prepayment price cap.

On 1 April 2019, the level of the prepayment price cap rose from £1,136 to £1,242 for a dual fuel customer who uses a typical amount of energy. This increase was mainly due to higher wholesale energy costs and network costs. For more information on the latest updates, see our chart Breakdown of the prepayment price cap.

Relevance and further information

This chart helps us track the differential between the average prepayment SVT and the market cheapest PPM tariff price a customer will pay if they use prepayment to pay their energy bills. Both prices are compared with the prepayment price cap that currently apply to all prepayment customers, excluding those on ‘interoperable’ smart meters.

Customers who get the Government’s Warm Home Discount (WHD) and are on a standard variable or default tariff were protected by a ‘safeguard tariff’ set at the level of the prepayment price cap until the end of 2018, after which they were transferred to the default tariff price cap. The default tariff price cap came into effect on 1 January 2019, limiting the amount that suppliers can charge customers on default tariffs.

The default tariff cap has different levels set to reflect how customers pay, where they live and the type of energy meter they have. When transferred, WHD customers will be placed on the cheaper default cap level set for direct debit payment methods – it won’t matter how they pay.

You can find further information on energy price caps here.

Methodology

  • We calculate the bill values associated with the different tariff types using a ‘typical medium domestic consumer’. As of October 2017, typical consumption values for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1).  
  • All prices shown are for a dual fuel customer (i.e. where a customer takes gas and electricity from the same supplier).  
  • The market average SVTs are based on the prices of the 12 largest suppliers in the prepayment segment. We have weighted the SVT of each supplier using an estimate of their total share of all prepayment accounts (for prepayment). We update the weightings every six months in January and July to reflect customer numbers four months prior to publication. The time lag is due to data availability. For example, the average given for 28 January 2017 uses weights based on customer numbers at 31 October 2016, while the average for 28 December 2016 uses weights at 31 March 2016.  
  • An SVT refers to a supply contract which is for a period of an indefinite length, and which does not have a fixed-term period applying to any of the terms and conditions. It’s an energy supplier’s basic offer. If a customer does not choose a specific energy plan, for example after their fixed tariff ends, they will be moved onto an SVT until they have chosen a new one. A customer can also make an active choice to select an SVT. 
  • We exclude tariffs with limited availability – such as tariffs only available to new customers (also known as ‘acquisition’ tariffs) or tariffs restricted to certain regions - when calculating the market cheapest tariff. This is so we give a representative picture of tariffs generally available to all customers across GB. 
  • We include tariffs available with ‘white label’ suppliers in our calculation of the cheapest tariffs. White label suppliers are organisations without supply licences that partner with an active licensed supplier to offer gas and electricity using their own brand. 
  • The cheapest tariff shown on the chart includes any collective switching tariffs after the first quarter of 2016. 
  • In all cases, the prices shown are based on suppliers’ tariffs averaged across GB regions. The level of the prepayment price cap is based on the values published on our website, adjusted to reflect current typical domestic consumption values, and to include VAT.

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Chart

Source: Suppliers.

Information correct as of: April 2019

This chart shows the number of domestic gas customer accounts for each of the six large and medium-sized suppliers, excluding those that primarily supply customers on prepayment meters. The number is broken down into five categories: accounts on a standard variable tariff (‘SVT’) held for three years or more with a supplier, accounts on an SVT held for less than three years with a supplier, accounts on fixed term default tariffs, accounts on other non-standard variable tariff and accounts on active choice fixed tariffs.

The chart is based on data provided to Ofgem by suppliers as of the snapshot date of 01 January 2019.

Click the ‘more information’ tab above for a summary of the key figures, details of how to interpret the figures and for information on our methodology.

Policy Areas:

  • Domestic consumers
  • Electricity - retail markets

Data Table

Number of domestic gas customer accounts by supplier (excluding pre-payment customers): Standard variable, fixed and other tariffs (GB)
Standard variable tariffs (3 years or more)Standard variable tariffs (less than 3 years)Fixed tariff - defaultOther non-standard variable tariffsFixed tariff - active choice
British Gas21174318564175895811809662067872
E.ON57893056380661003093
SSE807668506637249059474727
ScottishPower207089300794184413179291065634
EDF Energy2351563869051081200
npower26717931842566851769
Bulb111714170
OVO Energy57702034643564478179
Shell Energy325881297288071617491759
Utility Warehouse9591010880615261762962
Octopus Energy1183482397248512
Co-operative Energy161075127658778600179335
Green Star Energy92783558124405

More information

At-a-glance summary

Focusing on the suppliers shown in the chart, with the exception of Bulb, as of January 2019, the overall proportion of domestic gas customer accounts on default tariffs (both standard variable and fixed default tariffs) not paying via the prepayment payment method was 50%. The number of domestic customer accounts on default tariffs are split between those accounts held for three years or more (26%), those held for less than three years (22%) and those on fixed default tariffs (4%). All other accounts were on actively chosen fixed tariffs (45%), and on other non-standard variable tariffs (3%). The proportions vary significantly across suppliers due to each supplier's business model, the characteristics of their customers and the tariffs they offer.

The above aggregated figures do not include Bulb’s customer accounts. This is because, as of January 2019, they offered only one variable tariff which, while being an SVT, was priced similarly to fixed tariffs and was used to acquire customers.

When considering electricity customer accounts on all payment methods, the proportion on default tariffs in January 2019, based on the data for the suppliers shown in the chart excluding Bulb, was 56%.

Relevance and further information

This chart tracks the number of domestic electricity customer accounts on different tariff types. We also publish a chart tracking the number of domestic electricity customer accounts on different tariff types. Along with other switching and consumer research statistics, these charts help us understand customer engagement with the energy market.

These should be considered jointly with our chart, Average tariff prices by supplier: Standard variable and fixed default vs cheapest available tariffs (GB).

Our data shows default tariffs are usually more expensive than other deals available in the market. Among the suppliers included in the chart, excluding Bulb, around 11 million domestic gas accounts (9 million excluding prepayment payment methods) were on default tariffs as of 1 January 2019. These customers are potentially missing out on significant savings on their bills compared to cheaper tariffs from their existing or another supplier. 

For previous updates, please see our page Standard variable tariff indicators - previous updates.

Methodology

This is an indicator of customer engagement with the tariff choice available in the market, which excludes prepayment customer accounts. This is because the availability of different tariff types for customers on prepayment is more limited than that for customers on credit payment methods. The indicator focuses on the licensed suppliers active in the market with more than 250,000 customer accounts, excluding suppliers which primarily supply to customers on prepayment meters.

The different tariff types that this chart refers to are:

Standard variable rate tariffs (‘SVT’)

An SVT is a supply contract with an indefinite length that does not have a fixed-term applying to the terms and conditions. It’s an energy supplier’s basic offer. If a customer does not choose a specific energy plan, for example after their fixed tariff ends, they are moved to an SVT until they choose a new one. A customer can also make an active choice to select an SVT.

Default Fixed tariff

Similar to a SVT, a default fixed term tariff is a tariff onto which a customer is rolled onto following the expiration of another fixed tariff. This tariff has a fixed price for a set period of time. At the end of this period, the customer will be rolled onto another fixed tariff.

Other non-standard variable tariffs

A non-standard variable tariff is a supply contract with an indefinite length that does not have a fixed-term applying to the terms and conditions and has also associated rewards schemes, bundles or added services. Any vacant properties are also included under this category.

Active Choice Fixed tariffs

A fixed tariff is a supply contract with terms and conditions which apply for a fixed period (for example, a contract offered by a supplier that has a standing and unit price that is fixed for a year). An active choice tariff is a tariff which a customer actively signs up to.

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Source: Suppliers.

Information correct as of: April 2019

This chart shows the number of domestic electricity customer accounts for each of the six large and medium-sized suppliers, excluding those that primarily supply customers on prepayment meters. The number is broken down into five categories: accounts on a standard variable tariff (‘SVT’) held for three years or more with a supplier, accounts on an SVT held for less than three years with a supplier, accounts on fixed term default tariffs, accounts on other non-standard variable tariff and accounts on active choice fixed tariffs.

The chart is based on data provided to Ofgem by suppliers as of the snapshot date of 01 January 2019.

Click the ‘more information’ tab above for a summary of the key figures, details of how to interpret the figures and for information on our methodology.

Policy Areas:

  • Domestic consumers
  • Electricity - retail markets

Data Table

Number of domestic electricity customer accounts by supplier (excluding pre-payment customers): Standard variable, fixed and other tariffs (GB)
Standard variable tariffs (3 years or more)Standard variable tariffs (less than 3 years)Fixed tariff - defaultOther non-standard variable tariffsFixed tariff - active choice
British Gas12170767757515221271771841857158
E.ON1075199812731111091286834
SSE1389132718149243216633028
EDF Energy6383216133391339904
ScottishPower393782461708235550163641258755
npower519731412786162211072796
Bulb135844374
OVO Energy1005425540612599563171
Shell Energy355031446618158657524267
Utility Warehouse11909411816817252270566
Octopus Energy1518303907293373
Co-operative Energy203756591165835729207420
Green Star Energy95390660130834

More information

At-a-glance summary

Focusing on the suppliers shown in the chart, with the exception of Bulb, as of January 2019, the overall proportion of domestic electricity customer accounts on default tariffs (both standard variable and fixed default tariffs) not paying via the prepayment payment method was 52%. The number of domestic customer accounts on default tariffs are split between those accounts held for three years or more (26%), those held for less than three years (22%) and those on fixed default tariffs (4%). All other accounts were on actively chosen fixed tariffs (45%), and on other non-standard variable tariffs (3%). The proportions vary significantly across suppliers due to each supplier's business model, the characteristics of their customers and the tariffs they offer.

The above aggregated figures do not include Bulb’s customer accounts. This is because, as of January 2019, they offered only one variable tariff which, while being an SVT, was priced similarly to fixed tariffs and was used to acquire customers.

When considering electricity customer accounts on all payment methods, the proportion on default tariffs in January 2019, based on the data for the suppliers shown in the chart excluding Bulb, was 58%

Relevance and further information

This chart tracks the number of domestic electricity customer accounts on different tariff types. We also publish a chart tracking the number of domestic gas customer accounts on different tariff types. Along with other switching and consumer research statistics, these charts help us understand customer engagement with the energy market.

These should be considered jointly with our chart, Average tariff prices by supplier: Standard variable and fixed default vs cheapest available tariffs (GB).

Our data shows default tariffs are usually more expensive than other deals available in the market. Among the suppliers included in the chart, excluding Bulb, around 14 million domestic electricity accounts (11 million excluding prepayment payment methods) were on default tariffs as of 1 January 2019. These customers are potentially missing out on significant savings on their bills compared to cheaper tariffs from their existing or another supplier. 

For previous updates, please see our page Standard variable tariff indicators - previous updates.

Methodology

This is an indicator of customer engagement with the tariff choice available in the market, which excludes prepayment customer accounts. This is because the availability of different tariff types for customers on prepayment is more limited than that for customers on credit payment methods. The indicator focuses on the licensed suppliers active in the market with more than 250,000 customer accounts, excluding suppliers which primarily supply to customers on prepayment meters.

The different tariff types that this chart refers to are:

Standard variable rate tariffs (‘SVT’)

An SVT is a supply contract with an indefinite length that does not have a fixed-term applying to the terms and conditions. It’s an energy supplier’s basic offer. If a customer does not choose a specific energy plan, for example after their fixed tariff ends, they are moved to an SVT until they choose a new one. A customer can also make an active choice to select an SVT.

Default Fixed tariff

Similar to a SVT, a default fixed term tariff is a tariff onto which a customer is rolled onto following the expiration of another fixed tariff. This tariff has a fixed price for a set period of time. At the end of this period, the customer will be rolled onto another fixed tariff.

Other non-standard variable tariffs

A non-standard variable tariff is a supply contract with an indefinite length that does not have a fixed-term applying to the terms and conditions and has also associated rewards schemes, bundles or added services. Any vacant properties are also included under this category.

Active Choice Fixed tariffs

A fixed tariff is a supply contract with terms and conditions which apply for a fixed period (for example, a contract offered by a supplier that has a standing and unit price that is fixed for a year). An active choice tariff is a tariff which a customer actively signs up to.

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Source: Companies’ consolidated segmental statements.

Information correct as of: August 2018

This chart shows the combined gas and electricity pre-tax domestic supply margins of the six large suppliers. It is based on information reported by the large suppliers in their annual Consolidated Segmental Statements.

We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the key figures, details of how to interpret the figures and for information on our methodology.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Pre-tax domestic supply margins of large suppliers, combined gas and electricity
British GasE.ONEDFnpowerScottishPowerSSEAggregate
20097.59%-2.62%-7.50%-6.93%1.72%2.31%0.89%
20108.88%0.48%-3.87%-4.66%-0.17%5.95%3.04%
20116.86%1.98%-4.84%-1.81%-0.43%5.77%2.80%
20126.64%2.26%-3.04%3.61%4.51%6.36%4.25%
20136.14%4.01%-2.76%3.41%4.77%3.91%3.94%
20145.30%5.06%-0.24%2.65%5.79%6.04%4.46%
20157.56%4.52%-0.69%-6.78%5.67%6.25%4.15%
20167.18%6.95%-0.87%-6.26%5.20%6.95%4.48%
20178.01%5.21%0.93%-4.88%0.46%6.83%4.20%

More information

Pre-tax supply margins of the largest suppliers: At-a-glance summary

Between 2009 and 2016, the average combined gas and electricity pre-tax domestic supply margin across the six large suppliers grew from around 1% to around 4%, with significant differences between the suppliers’ margins.

Between 2016 and 2017, profits earned by the six large suppliers continued to vary substantially, but showed a decrease in the average combined gas and electricity pre-tax domestic supply margin from 4.5% to 4.2%. EDF returned to profit, reporting increasing domestic margins year-on-year from -0.9% to 0.9%, while npower reported higher domestic margins, despite making the biggest loss (-4.9%). British Gas also reported an increase in domestic margins and continued to earn the highest margins amongst the six large suppliers (8%). E.ON and SSE showed a decreasing trend, while ScottishPower reported a large fall in domestic margins year-on-year from 5.2% to 0.5%.

Relevance and further information

This chart helps us understand trends in profits in the domestic supply market and how they differ between suppliers.

Methodology

The supply margins shown in this chart are the ratio between a company’s Earnings Before Interest and Taxes (EBIT) - the ‘pre-tax margin’ - and its total revenues from supplying gas and electricity.

A supplier’s pre-tax margin is calculated by subtracting from a company’s total revenue its total direct costs, total indirect costs (such as operating costs), depreciation and amortisation for supplying energy.

Figures are calculated using information from companies’ annual Consolidated Segmental Statements. They relate to the suppliers’ financial years. Five of the companies (British Gas, EDF, E.ON, npower and ScottishPower) have financial years ending in December, whereas SSE’s financial year runs from April to March. 

The data in this chart may differ from the data that can be found in the company’s externally-published Consolidated Segmental Statements. This is because we have made some adjustments to the way in which exceptional items are reported among suppliers to improve comparability.

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Javascript is required to render chart Large suppliers: Domestic dual fuel bill breakdown over time.

Source: Ofgem analysis of companies’ Consolidated Segmental Statements.

Information correct as of: August 2018

This chart provides an estimate of the breakdown of a dual fuel bill over time for an average domestic customer of the large suppliers.  It is based on information reported by the large suppliers in their annual Consolidated Segmental Statements. For more information, please see our page Understanding the profits of the large energy suppliers. Earnings Before Interest and Tax (EBIT) – which we also refer to as suppliers’ pre-tax margins – are calculated as revenue minus costs, before accounting for taxes and interest.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Large suppliers: Domestic dual fuel bill breakdown over time
Wholesale costsDirect costsNetwork costsEnvironmental/social costsOther direct costsOperating costsEBITVATBill
20096212901328521095
201058828016035531116
201153728715230501057
201261234716153591232
2013628276109016349611286
2014532278100516651571190
201550627986718249551165
2016425292911319354531123
20174042841081420549531117

More information

Domestic dual fuel bill breakdown over time: At-a-glance summary

Between 2009 and 2017, the average domestic dual fuel bill has fluctuated in the range of £1,095 to £1,286. The average domestic dual fuel bill decreased between 2016 and 2017 as a result of a reduction in wholesale and network costs, which was partially offset by increases in environmental/social costs and operating costs.

The large suppliers’ financial statements have shown a marked difference in outturns for gas and electricity. Despite the fall in revenues, aggregate pre-tax profits from the supply of gas increased year-on-year, while for electricity they fell significantly.

Relevance and further information

This indicator helps to explain the costs making up an average dual fuel bill and show the factors influencing total bills in a given year. The costs that make up a bill are wholesale costs, network costs, environmental and social obligation costs, operating costs (including depreciation and amortisation), supplier pre-tax margin and VAT.

Methodology

To estimate the breakdown of an average gas and electricity bill, we took the sum of each category of costs and pre-tax supply margins as reported by the suppliers for each fuel and then divided by the total number of customers for that fuel. We then added VAT at 5% and summed the implied bill components for gas and electricity together to derive an estimate of the overall costs making up a dual fuel bill.

Note that because it is based on the total costs and customer numbers reported by suppliers irrespective of their tariff type, the bill breakdown for gas will reflect a mixture of the costs of serving gas to dual fuel and single fuel customers – and the same also applies to electricity. As such, the dual fuel breakdown should be considered an approximation in that it will reflect a combination of the costs incurred in serving gas and electricity to both dual fuel and single fuel customers (which may differ if, for example, electricity-only customers consume more electricity than those customers that are also supplied with gas).

The data presented is based on the latest available Consolidated Segmental Statements. It may differ from the data that can be found in the supplier’s externally published Consolidated Segmental Statements. This is because we have made some adjustments to the way in which exceptional items are reported among suppliers to improve comparability.

Figures relate to the suppliers’ financial years. Five of the companies (British Gas, EDF, E.ON, npower and ScottishPower) have financial years ending in December, whereas SSE’s financial year runs from April to March.

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Javascript is required to render chart Breakdown of the prepayment price cap (GBP £).

Source: Ofgem analysis.

Information correct as of: February 2019

This chart shows a breakdown of the costs that make up the prepayment meter price cap. It helps to explain the relationship between the level of the prepayment price cap we set, and the different cost factors that influence it each time we update it. We update this chart in February and August, to reflect the levels of the prepayment price cap that will come into effect in April and October.

The prepayment price cap limits how much a supplier can charge customers on prepayment meters per unit of energy. It doesn’t cap the total cost of a bill. That’s because the amount customers pay also depends on how much gas or electricity they’ve used. Suppliers can charge less than the set level of the cap, but not more. All prices shown here are for a dual fuel customer with typical energy use.

We extended the prepayment price cap to a further one million vulnerable customers in receipt of the government’s Warm Home Discount who were on a standard variable or default energy tariff on 2 February 2018 (under the label of a ‘safeguard tariff’). These customers transferred to the broader price cap for customers on default energy tariffs when it became effective on 1 January 2019.

Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the component costs and allowances, and for information on our methodology.

For a detailed breakdown of the cap by meter type and region, please see our page for the latest level for 1 April to 30 September 2019.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of the prepayment price cap (GBP £)
Wholesale costsNetwork costsPolicy costsOther, indirect cost allowancePrepayment uplift allowanceHeadroom allowanceVAT
2017 summer361257125166642850
2017/18 winter352258112168652749
2018 summer378258135171662952
2018/19 winter421257134172673154
2019 summer493271144174673459

More information

At-a-glance summary

  • We update the level of the prepayment price cap on 1 April and 1 October each year. The update on 1 April 2019 will increase the set level by £106 from its previous level at 1 October 2018.
  • The rise in the tariff level reflects increases in wholesale, network, and policy costs.
  • Other categories of costs remained largely unchanged. These categories are the costs to comply with social and environmental government schemes, network costs, operating costs, costs specifically associated with prepayment meters and ‘headroom’, which is designed to allow suppliers to offer competitive deals underneath the cap.

Relevance and further information

This chart summarises the different costs that make up the prepayment meter price cap applying to customers with prepayment meters (excluding those with fully interoperable smart meters). 

The Competition and Markets Authority introduced the price protection of a price cap to prepayment meter customers, who can’t easily access the cheapest tariffs, in April 2017. These customers are often in vulnerable circumstances. They designed the tariff based on a broad estimate of how much it costs an efficient supplier to provide gas and/or electricity to certain groups of customers. 

As the energy regulator, Ofgem administers and calculates the level for the cap.

We update the level of the tariff every six months, either reflecting changes in underlying costs, or increases in inflation. Our calculations cover:

  • wholesale energy costs: how much a supplier has to pay to get the gas and electricity to supply households with energy (we base this on forward prices for energy to be delivered over a 12-month period);
  • network costs: the regional costs of building, maintaining and operating the pipes and wires that carry energy across the country to households;
  • policy costs: the costs related to government social and environmental schemes to save energy, reduce emissions and encourage take-up of renewable energy;
  • other, indirect cost allowance: this includes operating costs and is inflated by the Consumer Price Index
  • prepayment uplift allowance: the additional costs involved in supplying prepayment customers compared to credit customers, which is inflated by CPI; and
  • headroom allowance: this allows suppliers to offer competitive deals underneath the set level of the prepayment price cap, and is calculated as a proportion of other cost elements.

Methodology

  • The level of the cap is based on calculations of wholesale costs, network costs, policy costs, operating costs and costs specifically associated with prepayment meters. It also includes a degree of ‘headroom’, which is designed to allow suppliers to offer competitive deals underneath the level we set for the prepayment price cap.
  • We calculate the bill values associated with the different tariff types using a ‘typical domestic consumer’ with ‘medium’ energy use. At October 2017, typical consumption values for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1). Find out more at Typical domestic consumption values.
  • All prices shown are for a dual fuel customer (i.e. where a customer takes gas and electricity from the same supplier). 
  • Further details of the methodology for calculating the level of the prepayment price cap can be found in the CMA Order and Explanatory Note
  • The figures presented here are calculated differently from the data on the domestic dual fuel bill breakdown over time for the large suppliers. This data is from the historical financial reporting by the large suppliers. The figures used to calculate the prepayment price cap are estimates across the whole market, and we make certain assumptions. For example, we calculate wholesale prices based on the forward prices for energy delivered over a 12-month period, but individual suppliers may differ in their purchasing strategies – some suppliers buying wholesale energy as much as two to three years in advance and some nearer the time that they launch their products.
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Javascript is required to render chart Breakdown of the default tariff price cap (GBP £).

Source: Ofgem.

Information correct as of: 7 February 2019

This chart shows a breakdown of the costs that make up the default tariff price cap for a dual-fuel, direct debit customer with typical consumption. It helps to explain the relationship between the level of the cap we set, and the different cost factors that influence it each time we update it.

The default tariff cap is effective from 1 January 2019. It has different levels set to reflect how you pay, where you live and the type of energy meter you have. For a detailed breakdown of the set cap prices by payment method, meter type and region, please see our industry page. Customers should contact their supplier for details specific to their tariff. 

The default tariff price cap limits how much a supplier can charge customers on default tariffs, including standard variable tariffs, per unit of energy. It doesn’t cap the total cost of a bill. That’s because the amount customers pay also depends on how much gas or electricity they’ve used. Suppliers can charge less than the set level of the cap, but not more. 

We update this chart every six months in February and August, to reflect the levels of the cap that will come into effect in April and October.

Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the component costs and allowances, and for information on our methodology.

Policy Areas:

  • Domestic consumers
  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of the default tariff price cap (GBP £)
Wholesale costsNetwork costsPolicy costsOperating costsEarnings Before Interest & Taxes (EBIT)VATPayment method uplift allowanceHeadroom allowance
2018/19 winter44725813719820541212
2019 summer52127015120422601213

More information

At-a-glance summary

  • The level of the tariff cap is based on the underlying costs required to supply energy. It applies from 1 January 2019.
  • We publish the level of the price cap in February and August to apply on 1 April and 1 October respectively each year.
  • The tariff level will reflect changes in the costs to supply energy. We determine how much each independent component of the cap should change by looking at external cost data. Details of the latest update can be found at Default tariff cap: 1 April 2019 to 30 September 2019.

Relevance and further information

This chart summarises the different costs that make up the default tariff price cap.

We update the level of the cap every six months, either reflecting changes in underlying costs, or increases in inflation. Our calculations cover:

  • wholesale energy costs: how much a supplier has to pay to get the gas and electricity to supply households with energy (we base this on forward prices for energy to be delivered over a 12-month period)
  • network costs: the regional costs of building, maintaining and operating the pipes and wires that carry energy across the country to households
  • policy costs: the costs related to government social and environmental schemes to save energy, reduce emissions and encourage take-up of renewable energy
  • operating costs: the costs incurred by suppliers to deliver billing and metering services, including smart metering
  • payment method uplift allowance: the additional costs incurred by suppliers to bill customers with different payment methods
  • headroom allowance: this allows suppliers to manage uncertainty in their costs, and also offer competitive deals beneath the set level of the cap.
  • Earnings Before Interest and Taxes (EBIT): a fair rate of return allowed for suppliers, to ensure they can finance their businesses.
  • VAT: 5% tax added to the level of the tariff.

Methodology

  • The level of the cap is based on calculations of the costs required for an efficient supplier to provide energy. It also includes some additional allowances to manage uncertainty, and ensure suppliers can finance their activities, amongst other things.
  • We calculate the bill values associated with the different tariff types using a ‘typical domestic consumer’ with ‘medium’ energy use. At October 2018, typical consumption values for a medium consumer are 12,000kWh/year for gas and 3,100kWh/year for electricity (profile class 1). Find out more at Typical domestic consumption values.
  • All prices shown are for a dual fuel customer paying by direct debit (i.e. where a customer takes gas and electricity from the same supplier). 
  • Further details of the methodology for calculating the level of the Default Tariff can be found in our statutory consultation on the default tariff cap and decision documents.

For a detailed breakdown of the cap by meter type and region, please see our page for the latest level for 1 April to 30 September 2019.

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Javascript is required to render chart Supplier Cost Index by fuel type (GB).

Source: Ofgem analysis.

Information correct as of: May 2018

The Supplier Cost Index tracks ongoing trends in wholesale costs, network costs and the charges to suppliers associated with government programmes.

This chart is no longer being updated.

At-a-glance summary

  • In the three months (between 1 February 2018 and 1 May 2018) the index increased by 5.3%, driven primarily by increases in wholesale gas and electricity costs. There was also a small increase in the costs of government obligations related to supplying electricity.
  • Overall, the Supplier Cost Index (dual fuel) increased by 14.1% between 1 May 2017 and 1 May 2018.
  • The 12 month increase was primarily driven by increases in wholesale gas and electricity costs.
  • The index starts in January 2015. Costs fell during 2015 and early 2016, with much larger reductions for gas than electricity. By the 1 May 2018, the dual fuel index is 9.7% above its level at the start of 2015. The electricity index is 19.7% higher, while the gas index is 0.1% higher.

Click the ‘more information’ tab above for a description of how the index is calculated and which costs are included.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Supplier Cost Index by fuel type (GB)
Expected supply costs for the next 12 months (Jan-15 = 100)Dual FuelElectricityGas
Jan-15100.0100.0100.0
Feb-1592.9995.3790.72
Mar-1596.7997.9895.66
Apr-1595.3096.4294.24
May-1594.9696.5893.42
Jun-1594.0096.3291.79
Jul-1593.6596.4990.94
Aug-1592.8496.3689.48
Sep-1590.7095.4586.18
Oct-1590.5195.9185.35
Nov-1589.1095.2483.24
Dec-1586.7494.6079.26
Jan-1685.1494.0876.61
Feb-1681.8091.7972.29
Mar-1681.4792.1071.35
Apr-1682.3893.5271.76
May-1683.2694.2572.79
Jun-1685.8896.4275.84
Jul-1691.18100.8581.97
Aug-1695.48104.6186.78
Sep-1693.09103.4283.24
Oct-1692.66104.3281.56
Nov-16104.35118.8690.51
Dec-16105.01118.9991.68
Jan-1798.77108.5089.49
Feb-17102.23109.9894.85
Mar-17100.41108.0393.14
Apr-1796.68105.4388.35
May-1796.06105.0787.48
Jun-1795.61105.0586.61
Jul-1796.18106.6486.22
Aug-1796.52107.6785.89
Sep-1799.70110.6789.25
Oct-17101.64112.1291.66
Nov-17103.12112.9593.76
Dec-17105.71114.4797.37
Jan-18106.70114.6699.12
Feb-18104.13113.5495.15
Mar-18102.91112.9393.36
Apr-18105.90116.0096.28
May-18109.65119.70100.07

More information

Methodology

  • We calculate the Supplier Cost Index by estimating trends in network charges, wholesale prices and the charges to suppliers associated with government programmes (note that in some cases, these government charges only apply to large and medium-sized suppliers).
  • These estimates are then combined with information on the relative scale of each of these categories of cost to calculate the trend in the overall Supplier Cost Index. The weights given to each category of costs are based on financial statements from the six large suppliers, and are as follows:

- wholesale electricity: 26.7%

- wholesale gas: 35.9%

- networks electricity: 15.4%

- networks gas: 14.4%

- government obligations electricity: 6.7%

- government obligations gas: 1.0%.

 

  • The index reflects estimated expected annual costs, covering the 12 months from the time of each update, based on the best information available at the time. So, for example, the value of the index for May 2018 will reflect estimated costs for the period 1 May 2018 to 30 April 2019, expressed relative to estimated expected annual costs as of the base period (1 January 2015 to 31 December 2015).
  • The estimates in the index are forward-looking, they therefore rely on forecasts and assumptions, and so will be subject to uncertainty. Information on suppliers’ realised costs is available in the financial statements published by the six large energy suppliers. See Understanding the profits of the large energy suppliers.
  • The index does not include estimates of suppliers' ‘back-office’ operating costs (such as the costs of billing or metering – including the costs of the smart meter rollout) or their profit margins, which suppliers will seek to cover when setting their prices.
  • The index is based on trends in the average prices of wholesale gas and electricity forward contracts in the month prior to the update. Suppliers will take different approaches to purchasing their wholesale energy, and many will buy their energy over an extended period. The index does not seek to estimate any impact this may have on a supplier’s costs.
  • Other elements of costs are also likely to vary across individual suppliers. For example, suppliers may have some flexibility in how they meet their obligations under government programmes. This could mean, for example, that suppliers see different year-on-year changes in costs than indicated by the index where they have chosen to meet their obligations under the ECO scheme at the start of the delivery period (the forecasts used in the index are based on a flat delivery profile). Network charges will also vary between suppliers depending on things like the regional profile of their customer base. 
  • The index is calculated for a customer with typical consumption. We have held consumption fixed over time to increase comparability with trends in suppliers’ prices (which are also typically expressed for a given level of consumption). In practice, energy use will vary from one year to the next, depending on temperatures. Energy use is also subject to long-run trends, for example as a result of increasing energy efficiency. Trends in consumption will also have a significant impact on the size of customers’ bills.
  • Capacity market payments were included in the index from winter 2017, we have categorised these as wholesale electricity costs. We consider that this allocation best reflects the nature of these costs. We intend to keep under review what further detail might be provided on the costs associated with different government programmes. 
  • Since the August 2017 update, we have included the additional costs associated with the expected exemption of Energy Intensive Industries from the costs of the Renewable Obligation scheme, following the Government’s announcement in December 2017. The Government’s decision on implementing the same exemption for the Feed-in Tariff scheme has yet to be published, and so the possible impact of a similar change to the way this programme is funded is not currently included.

Further details of how we calculate the index are provided in our methodology document.

 

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Source: Ofgem analysis.

Information correct as of: May 2018

This chart shows the contribution of trends in different cost categories to the overall year-on-year change in the Supplier Cost Index.

This chart is no longer being updated.

At-a-glance summary

Between May 2017 and May 2018, the Supplier Cost Index increased by 14.1%.

  • The increase was primarily driven by increases in the wholesale costs of both gas and electricity accounting for 12 percentage points of the 14.1% increase in the index. Wholesale gas prices have increased slightly more than wholesale electricity prices.
  • The costs of government obligations related to supplying electricity (particularly programmes associated with supporting renewable and low-carbon electricity generation). These costs increased the dual fuel index by 1.9 percentage points.
  • The costs of government obligations related to supplying gas have remained largely unchanged.
  • There were in addition, smaller increases in network charges related to supplying gas, which are very nearly offset by a reduction in network costs related to supplying electricity.

We update this chart on a quarterly basis. Click the ‘more information’ tab above for details of how to interpret the figures in the chart and for information on how the index has been calculated.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of the year-on-year change in the Supplier Cost Index
Impact on Cost Index (May 2018 vs. May 2017)
Wholesale (electricity)5.8
Wholesale (gas)6.2
Network (electricity)-0.3
Network (gas)0.5
Government obligations (electricity)1.9
Government obligations (gas)0.0

More information

How to interpret the year-on-year change in the Supplier Cost Index

The breakdown is calculated by combining the percentage change in each category of expected costs, with an estimate of the importance of that cost to suppliers' total costs. Adding the bars together gives the overall change in the index.

Note, therefore, that the percentages shown are not the same as the percentage change in the individual categories of costs. For example, if the chart shows a one percentage point contribution for wholesale gas this does not mean that wholesale gas costs have risen by 1%, rather that there has been an increase in wholesale gas costs which has caused the overall cost index to rise by 1%. As wholesale gas costs make up only one part of suppliers' overall costs, the percentage increase in these costs would have been significantly higher to result in a 1% increase in the overall cost index.

It is important to bear in mind that the contributions shown relate only to the direct charges to suppliers associated with the different types of costs, and do not take into account the relationships between the categories.

For instance, trends in network charges to electricity generators are not included in the ‘network charges’ component of the breakdown, as they are not paid directly by suppliers – and will instead affect wholesale electricity prices. To give another example, a reduction in wholesale prices (and so the wholesale cost component of the index) will be associated with an increase in supplier payments to fund Contracts for Difference, which support low carbon electricity generation.

For this reason, the contribution of different types of costs to the index cannot be interpreted as showing the totality of the impact of government policies or network charges on consumers’ bills.

Methodology

  • We calculate the Supplier Cost Index by estimating trends in network charges, wholesale prices and the charges to suppliers associated with government programmes (note that in some cases, these government charges only apply to large and medium-sized suppliers).
  • These estimates are then combined with information on the relative scale of each of these categories of cost to calculate the trend in the overall Supplier Cost Index. The weights given to each category of costs are based on financial statements from the six large suppliers, and are as follows:

- wholesale electricity: 26.7%

- wholesale gas: 35.9%

- networks electricity: 15.4%

- networks gas: 14.4%

- government obligations electricity: 6.7%

- government obligations gas: 1.0%.

 

  • The index reflects estimated expected annual costs, covering the 12 months from the time of each update, based on the best information available at the time. So, for example, the value of the index for May 2018 will reflect estimated costs for the period 1 May 2018 to 30 April 2019, expressed relative to estimated expected annual costs as of the base period (1 January 2015 to 31 December 2015).
  • The estimates in the index are forward-looking, they therefore rely on forecasts and assumptions, and so will be subject to uncertainty. Information on suppliers’ realised costs is available in the financial statements published by the six large energy suppliers. See Understanding the profits of the large energy suppliers.
  • The index does not include estimates of suppliers' ‘back-office’ operating costs (such as the costs of billing or metering – including the costs of the smart meter rollout) or their profit margins, which suppliers will seek to cover when setting their prices.
  • The index is based on trends in the average prices of wholesale gas and electricity forward contracts in the month prior to the update. Suppliers will take different approaches to purchasing their wholesale energy, and many will buy their energy over an extended period. The index does not seek to estimate any impact this may have on a supplier’s costs.
  • Other elements of costs are also likely to vary across individual suppliers. For example, suppliers may have some flexibility in how they meet their obligations under government programmes. This could mean, for example, that suppliers see different year-on-year changes in costs than indicated by the index where they have chosen to meet their obligations under the ECO scheme at the start of the delivery period (the forecasts used in the index are based on a flat delivery profile). Network charges will also vary between suppliers depending on things like the regional profile of their customer base. 
  • The index is calculated for a customer with typical consumption. We have held consumption fixed over time to increase comparability with trends in suppliers’ prices (which are also typically expressed for a given level of consumption). In practice, energy use will vary from one year to the next, depending on temperatures. Energy use is also subject to long-run trends, for example as a result of increasing energy efficiency. Trends in consumption will also have a significant impact on the size of customers’ bills.
  • Capacity market payments were included in the index from winter 2017, we have categorised these as wholesale electricity costs. We consider that this allocation best reflects the nature of these costs. We intend to keep under review what further detail might be provided on the costs associated with different government programmes. 
  • Since the August 2017 update, we have included the additional costs associated with the expected exemption of Energy Intensive Industries from the costs of the Renewable Obligation scheme, following the Government’s announcement in December 2017. The Government’s decision on implementing the same exemption for the Feed-in Tariff scheme has yet to be published, and so the possible impact of a similar change to the way this programme is funded is not currently included.

Further details of how we calculate the index are provided in our methodology document.

Further information

This chart is part of our quarterly update to the Supplier Cost Index. For further details, see Understanding the profits of the large energy suppliers.

 

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Switching and consumer experience

Consumers promote effective competition by being actively engaged in managing their energy, and making a credible threat of switching where better offers are available. This pressures suppliers to innovate and offer better products and services for them.

We look at trends in external switching (between suppliers) and internal switching (with the same supplier) to understand levels of consumer engagement. We also look at average switching times, an indicator of process quality, and consider trends in overall consumer satisfaction with suppliers. These indicators are a snapshot of our more detailed consumer research on market engagement.

Chart

Source: Ofgem analysis of data from electricity distribution network operators (DNOs) and Xoserve.

Information correct as of: May 2019

This chart shows the total number of domestic customers switching gas and electricity supplier each month. It also shows, in dotted lines, the number of switches going to medium/small suppliers, as well as the net gains made by these suppliers (from November 2016).

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Number of domestic customers switching supplier by fuel type (GB)
MonthTotal electricity switchesTotal gas switchesSwitches to electricity other suppliersSwitches to gas other suppliersNet gains for electricity other suppliersNet gains for gas other suppliers
01/01/2003326,000266,000
01/02/2003337,000167,000
01/03/2003368,000239,000
01/04/2003351,000216,000
01/05/200332,7000245,000
01/06/2003344,000252,000
01/07/2003365,000260,000
01/08/2003318,000253,000
01/09/2003382,000296,000
01/10/2003370,000290,000
01/11/2003344,000280,000
01/12/2003371,000294,000
01/01/2004273,000303,000
01/02/2004341,000256,000
01/03/2004412,000334,000
01/04/2004341,000283,000
01/05/2004310,000266,000
01/06/2004356,000297,000
01/07/2004323,000275,000
01/08/2004331,000261,000
01/09/2004367,000276,000
01/10/2004406,000338,000
01/11/2004398,000370,000
01/12/2004340,000330,000
01/01/2005243,000281,000
01/02/2005359,000181,000
01/03/2005390,000302,000
01/04/2005384,000341,000
01/05/2005369,000304,000
01/06/2005365,000317,000
01/07/2005330,000271,000
01/08/2005375,000286,000
01/09/2005348,000298,000
01/10/2005416,000301,000
01/11/2005465,000329,000
01/12/2005361,000300,000
01/01/2006284,000290,000
01/02/2006347,000208,000
01/03/2006539,000366,000
01/04/2006418,000345,000
01/05/2006396,000372,000
01/06/2006364,000350,000
01/07/2006360,000295,000
01/08/2006428,000315,000
01/09/2006402,000358,000
01/10/2006429,000356,000
01/11/2006482,000374,000
01/12/2006392,000288,000
01/01/2007352,000346,000
01/02/2007390,000265,000
01/03/2007441,000333,000
01/04/2007392,000301,000
01/05/2007452,000334,000
01/06/2007426,000378,000
01/07/2007441,000352,000
01/08/2007501,000336,000
01/09/2007397,000289,000
01/10/2007477,000383,000
01/11/2007477,000343,000
01/12/2007411,000322,000
01/01/2008335,000344,000
01/02/2008441,000278,000
01/03/2008476,000313,000
01/04/2008438,000388,000
01/05/2008440,000335,000
01/06/2008459,000347,000
01/07/2008474,000361,000
01/08/2008553,000348,000
01/09/2008466,000427,000
01/10/2008478,000347,000
01/11/2008428,000336,000
01/12/2008439,000332,000
01/01/2009290,000331,000
01/02/2009364,000255,000
01/03/2009475,000311,000
01/04/2009423,000298,000
01/05/2009397,000324,000
01/06/2009434,000332,000
01/07/2009442,000327,000
01/08/2009388,000304,000
01/09/2009480,000343,000
01/10/2009455,000336,000
01/11/2009441,000330,000
01/12/2009438,000332,000
01/01/2010259,000307,0006,622
01/02/2010353,000217,0008,884
01/03/2010460,000316,0007,735
01/04/2010379,000307,0009,193
01/05/2010352,000271,0007,564
01/06/2010413,000289,0002,986
01/07/2010398,000292,0003,007
01/08/2010419,000296,0003,928
01/09/2010426,000305,0006,836
01/10/2010409,000305,0004,253
01/11/2010456,000322,00010,827
01/12/2010425,000328,00011,251
01/01/2011270,000279,0003,280
01/02/2011324,000211,0006,340
01/03/2011400,000307,0006,597
01/04/2011360,000246,0004,273
01/05/2011356,000308,0007,479
01/06/2011393,000259,0008,895
01/07/2011397,000301,0008,868
01/08/2011449,000343,00016,021
01/09/2011343,000309,00013,281
01/10/2011326,000247,00019,478
01/11/2011329,000240,00019,854
01/12/2011259,000219,00012,620
01/01/2012210,000194,00022,337
01/02/2012257,000149,00029,128
01/03/2012279,000190,00020,817
01/04/2012232,000176,00012,872
01/05/2012286,000202,00019,167
01/06/2012272,000192,00041,228
01/07/2012257,000190,00018,762
01/08/2012265,000187,00013,366
01/09/2012312,000195,00022,561
01/10/2012366,000273,00072,968
01/11/2012338,000174,00066,652
01/12/2012266,000159,00050,393
01/01/2013228,000157,92943,231
01/02/2013247,000117,96449,082
01/03/2013247,000144,21329,156
01/04/2013251,000186,69029,311
01/05/2013234,000155,03124,985
01/06/2013218,000148,45335,281
01/07/2013232,000160,79331,292
01/08/2013210,000140,74932,638
01/09/2013254,000145,41427,969
01/10/2013381,186213,58971,447
01/11/2013606,061358,799138,394
01/12/2013309,978260,32593,626
01/01/2014214,944188,87093,57973,618
01/02/2014253,295169,946106,70877,109
01/03/2014269,497195,773134,80292,080
01/04/2014252,047201,512133,319104,617
01/05/2014228,628179,604124,802100,417
01/06/2014201,381163,56898,58687,363
01/07/2014219,026145,714104,62573,414
01/08/2014223,581150,623113,96076,153
01/09/2014283,877180,965138,186102,117
01/10/2014309,890232,178118,527108,942
01/11/2014270,603216,783108,79388,088
01/12/2014311,298250,638103,86781,917
01/01/2015190,554155,78973,97758,597
01/02/2015291,341230,518102,44590,566
01/03/2015382,809304,679135,965103,196
01/04/2015272,996214,556108,97679,892
01/05/2015239,574197,166108,49988,984
01/06/2015229,825174,688105,81483,896
01/07/2015239,343192,299108,28786,631
01/08/2015253,099195,183116,63393,783
01/09/2015279,411223,703128,043100,534
01/10/2015349,278274,581161,602121,335
01/11/2015343,870274,206161,034131,736
01/12/2015310,293242,630148,668117,677
01/01/2016245,922189,143139,539109,708
01/02/2016390,645305,057176,036143,238
01/03/2016453,964361,399244,232196,273
01/04/2016386,456273,751204,748151,645
01/05/2016345,146261,324169,711127,352
01/06/2016335,879252,712143,231104,67464,39143,204
01/07/2016303,404221,175140,898103,66270,82950,962
01/08/2016310,132209,178149,026108,99774,44557,084
01/09/2016349,203271,374154,142116,03268,91647,780
01/10/2016486,878384,023150,747118,32820,32816,409
01/11/2016386,585297,468147,607116,24536,64423,680
01/12/2016423,068317,740230,753176,05191,05368,890
01/01/2017319,503239,759203630158,23097,49678,267
01/02/2017398,150296,055220,784173,226107,16787,624
01/03/2017512,855388,103280,224223,528142,15511,3040
01/04/2017449,463327,288274,019212,426143,76711,4270
01/05/2017414,285304,615251,465193,355124,32799,986
01/06/2017379345315,542198,431166,62787,24076,388
01/07/2017350,660306,437177,209158,63972,36067,784
01/08/2017414,308348,605221,136191,41997,84796,690
01/09/2017520,678454,861276,304242,592155,301140,919
01/10/2017534,746460,559310,969273,286180,672165,424
01/11/2017440,757375,183222,992191,178108,57397,449
01/12/2017385,060325,882298,250196,213111,63099,215
01/01/2018321,560253,513192,655163,57289,56575,444
01/02/2018425,147347,711277,930227,017123,955102,203
01/03/2018443,326374,228221,536213,96298,95985,549
01/04/2018446,530371,819266,409216,622107,63982,419
01/05/2018464,753399,163320,163272,863164,128142,678
01/06/2018455,194388,672348,591298,865218,509188,196
01/07/2018442,406364,991299,457248,923177,140150,162
01/08/2018466,898394,160279,178205,354148,566128,367
01/09/2018525,216433,386329,664266,263163,805140,687
01/10/2018558,583469,695345,347286,553143,789121,562
01/11/2018462,137381,638242,454194,51477,58463,699
01/12/2018390,540338,140254,810206,693107,87577,370
01/01/2019360,286291,442241,517194,79699,07384,169
01/02/2019436,164350,030289,566227,009115,31592,266
01/03/2019585,775486,248403,017330,297191,480143,012

More information

At-a-glance summary

The number of domestic gas and electricity switches generally follows a seasonal pattern (with peaks around March and November then dipping in January and the summer months). Switching has been on the rise since 2014. The number of domestic switches in the 12 months up to March 2019 was 10% higher than in the 12 months up to March 2018 for electricity and 11% higher for gas.  

There has been a break in the usual seasonal switching pattern with the number of switches staying at a relatively constant level for each month since February 2018 instead of falling in the summer months, as we have historically seen. Switching in Q1 2019 has been historically high, with the number of electricity and gas switches in March 2019 reaching their highest level ever recorded in this month.

In March 2019 the proportion of net gains in switching away from the six large suppliers made up 27% of total switches for gas and electricity combined, up from 23% in March 2018.

Relevance and further information

External switching, from one supplier to another, is one measure of consumer engagement with the market. The number of switches to small and medium sized suppliers show how these suppliers are attracting customers over time. For summary information on the switching figures for the year please see also the facts and figures.

Methodology

The number of customers switching supplier shown in the graph is based on the number of meter points a supplier gains from another following a customer choice to change their supplier.

The net gains for small and medium suppliers is calculated by subtracting from the gross meter point gains these suppliers achieve over the month the gross number of meter points these suppliers lose over the same period.

As of July 2017, supply points connected to independent gas transporters are included in the gas data provided by Xoserve.

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Chart

Source: Six large suppliers.

Information correct as of: April 2019

This chart shows the proportion of monthly internal switches for domestic gas and electricity customer accounts for the six large suppliers. As a benchmark, the chart also shows monthly external switching rates (ie to another supplier) for the whole market.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Large suppliers: Internal and external switching rate by fuel type (GB)
Electricity total internal switching rateGas total internal switching rateElectricity total external switching rateGas total external switching rateElectricity internal switching rate by tariffGas internal switching rate by tariff
Nov-145.03%5.70%0.89%1.03%2.34%2.77%
Dec-144.21%4.75%1.13%1.19%1.86%2.14%
Jan-154.78%5.61%0.69%0.74%2.91%3.54%
Feb-155.22%5.96%0.94%1.10%2.89%3.34%
Mar-155.26%5.94%1.38%1.45%3.40%3.93%
Apr-155.41%6.21%0.99%1.02%2.70%3.15%
May-153.84%4.26%0.97%0.94%1.69%1.89%
Jun-153.14%3.38%0.83%0.83%1.61%1.75%
Jul-153.34%3.64%0.86%0.91%1.82%2.01%
Aug-153.95%4.29%0.91%0.93%1.76%1.89%
Sep-153.50%3.80%1.01%1.06%1.98%2.19%
Oct-153.78%4.15%1.26%1.31%2.02%2.24%
Nov-153.92%4.25%1.24%1.30%2.10%2.31%
Dec-153.31%3.55%1.11%1.15%1.67%1.76%
Jan-164.78%5.39%0.88%0.90%3.00%3.46%
Feb-165.00%5.54%1.40%1.45%3.15%3.53%
Mar-164.88%5.40%1.63%1.72%2.72%3.08%
Apr-164.40%4.80%1.38%1.30%2.28%2.56%
May-163.82%4.23%1.24%1.24%2.12%2.37%
Jun-164.43%4.82%1.20%1.20%2.28%2.48%
Jul-164.26%4.59%1.09%1.05%1.95%2.07%
Aug-162.82%2.98%1.11%0.99%1.55%1.65%
Sep-163.90%6.26%1.25%1.29%1.99%2.09%
Oct-165.10%5.48%1.74%1.82%2.12%2.23%
Nov-164.45%4.85%1.38%1.41%2.05%2.25%
Dec-163.14%3.41%1.51%1.51%1.33%1.47%
Jan-174.33%4.81%1.14%1.14%2.18%2.46%
Feb-175.46%6.02%1.42%1.40%2.93%3.28%
Mar-175.11%5.51%1.83%1.84%2.91%3.19%
Apr-174.73%5.20%1.60%1.55%2.92%3.22%
May-174.46%4.78%1.47%1.45%2.23%2.33%
Jun-174.02%4.36%1.35%1.37%1.97%2.19%
Jul-173.76%4.04%1.25%1.33%2.15%2.37%
Aug-174.35%4.50%1.47%1.51%1.86%2.07%
Sep-174.24%4.31%1.85%1.96%1.85%2.07%
Oct-174.28%4.60%1.89%1.99%2.03%2.29%
Nov-174.16%4.48%1.56%1.62%2.17%2.40%
Dec-174.42%4.78%1.36%1.40%1.66%1.80%
Jan-184.06%4.37%1.14%1.09%2.13%2.31%
Feb-184.91%5.12%1.50%1.50%3.06%3.19%
Mar-184.97%5.33%1.57%1.61%2.90%3.18%
Apr-186.94%7.35%1.58%1.60%3.29%3.43%
May-186.04%6.61%1.64%1.72%2.10%2.33%
Jun-186.08%6.33%1.61%1.67%3.43%3.58%
Jul-185.53%6.05%1.56%1.57%2.48%2.63%
Aug-185.70%6.03%1.65%1.69%3.42%3.55%
Sep-186.62%7.13%1.85%1.86%2.76%2.98%
Oct-184.51%4.92%1.97%2.01%2.08%2.23%
Nov-184.03%4.32%1.63%1.63%1.97%2.05%
Dec-183.21%3.33%1.37%1.45%1.62%1.62%

More information

At-a-glance summary

Internal switching rates among the six large suppliers have been consistently higher than external switching rates, with regular seasonal spikes in Spring and Autumn.

There was a break in the usual seasonal fall in both internal and external switching rates in Q2 2018. There was a large increase in the internal switching rate for both electricity and gas. The internal and external switching rates remained high in Q3 2018, relative to previous quarters. They then fell in Q4 2018 to levels below the corresponding rates in the previous year.

Relevance and further information

Together, internal and external switching rates provide a more comprehensive indicator of how engaged consumers are in the domestic retail energy market.

To note, we also publish monthly switching numbers separately. The two sets of data use different sources, and run to different timescales.

Methodology 

Internal total switching refers to a customer changing tariff, payment method or account management (online/offline) with their existing supplier. 

Internal tariff switching only includes tariff changes that, as a minimum, represent ‘active choices’. For example, the observed switch from a ‘dead’ tariff or an existing fixed tariff to a default standard variable tariff may not reflect an active choice and is not included in the internal tariff switching rate.

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Chart

Javascript is required to render chart Average switching time for domestic customers (GB) .

Source: Ofgem analysis of electricity distribution network operator (DNO) and Xoserve (gas) data.

Information correct as of: April 2019

This chart shows a month-on-month view of the average time it takes for a domestic customer to switch supplier.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Average switching time for domestic customers (GB)
MonthAverage electricity switching timeAverage gas switching time
01/01/201424
01/02/201423
01/03/20141822
01/04/20141823
01/05/20141823
01/06/20141824
01/07/20141722
01/08/20141822
01/09/20141822
01/10/20141822
01/11/20141821
01/12/20141620
01/01/20151620
01/02/20151516
01/03/20151615
01/04/20151616
01/05/20151516
01/06/20151616
01/07/20151616
01/08/20151616
01/09/20151618
01/10/20151517
01/11/20151517
01/12/20151618
01/01/20161618
01/02/20161618
01/03/20161617
01/04/20161617
01/05/20161617
01/06/20161617
01/07/20161617
01/08/20161617
01/09/20161616
01/10/20161516
01/11/20161616
01/12/20161517
01/01/20171617
01/02/20171516
01/03/20171616
01/04/20171617
01/05/20171517
01/06/20171515
01/07/20171619
01/08/20171518
01/09/20171618
01/10/20171517
01/11/20171517
01/12/20171617
01/01/20181718
01/02/20181318
01/03/20181817
01/04/20181518
01/05/20181518
01/06/20181718
01/07/20181718
01/08/20181718
01/09/20181618
01/10/20181618
01/11/20181617
01/12/20181618

More information

At-a-glance summary

Between January 2014 and December 2018, the average switching time for gas fell by 7 days to 18 days. The average switching time for electricity has been relatively steady since the end of 2014 between 15 and 17 days.

Relevance and further information

The average switching time is a useful indicator of how long a switch takes to complete. This affects a customer’s incentive and ability to take advantage of the best offers available in the market.

Methodology

Supply licences require licensees to take all reasonable steps to complete a transfer 21 days after the end of the 14 day cooling-off period (or after an earlier date during the cooling-off if agreed with the customer).

Switching time is measured here by the number of calendar days it takes from when a supplier submits a switching request to the transfer taking place. We source our data from distribution network operators, so our analysis does not reflect the time taken by the supplier to submit a switching request, which may happen at the end or during the cooling-off period, nor the additional time to process the contract with the customer.

As of July 2017, supply points connected to independent gas transporters are included in the gas data provided by Xoserve.

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Methodology and sources

We have selected this range of indicators to support general understanding of the market, including how they contribute to the consumer outcomes outlined in our corporate strategy. We also aim to provide a picture of the market where it is not produced elsewhere, or where there is scope for us to set a clear methodology for the data.

Our data comes from sources that are either publicly available, provided by third parties or from responses to Ofgem information requests. Specific sources and relevant dates are listed with each indicator. We are grateful to third parties for allowing us to reproduce their data. 

Most of these indicators will be updated quarterly while still allowing access to historic information. Updates will depend on the availability of data for an indicator. 

We will review the indicators periodically to ensure they continue to help promote transparency and understanding of the retail energy market and as additional sources of information become available.

Related publications

State of the energy markets 2018

State of the energy markets 2017

Retail energy markets in 2016

Retail energy markets in 2015

State of the market assessment 2014

These market indicators and data are not intended for use or to be relied on for any commercial purposes. View copyright and disclaimer

Publications and updates

  • Published: 28th Mar 2019
  • Charts and data
  • 1 Associated documents
Upcoming release dates for our market indicators and data on the Ofgem Data Portal.