All Available Charts

Showing page 1 of 1

Chart

Source: Companies’ consolidated segmental statements.

Information correct as of: August 2019

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%
20186.74%-0.28%1.76%-4.32%4.16%2.46%2.74%

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 2018, 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 2.7%.  E.ON and SSE saw a significant reduction in their margins, down to 0% and 2% respectively. In contrast, both EDF and ScottishPower’s profit margins increased, while npower saw a slight reduction in its losses. British Gas experienced the smallest change, with its profit margin only slightly down to 7% from 8% in 2017.

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.

close

Chart

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 2019

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
20184452811341621733561184

More information

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

Between 2009 and 2018, the average domestic dual fuel bill has fluctuated, reaching a peak of £1,286 in 2013. In 2018 it increased to £1,184 from £1,117 in 2017, mainly as a result of an increase in wholesale and environmental/social 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.

close

Chart

Javascript is required to render chart Breakdown of a gas bill.

Source: Companies’ consolidated segmental statements.

Information correct as of: August 2019

This chart shows an estimate of the different costs that make up an average gas bill for a typical domestic customer of the six large suppliers. It is based on reported data from the six large suppliers’ annual Consolidated Segmental Statements.

Click the ‘more information’ tab above for information on our methodology.

For information on supplier prices and profits, please see our page Understanding the profits of the large energy suppliers.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of a gas bill
Annual costPercentage
Wholesale costs43.22%
Networks24.44%
Operating costs19.43%
Environmental and social obligation costs1.60%
VAT4.76%
Supplier pre-tax margin5.05%
Other direct costs1.51%

More information

Methodology

To estimate the breakdown of an average gas bill, we:

  1. Took the sum of each category of cost (e.g. wholesale, network etc) and the pre-tax supply margin reported by the suppliers for gas.
  2. Divided the gas sum by the total number of customers and added VAT at 5%.

Please note that chart calculations are drawn from suppliers’ reported total costs and total customer numbers, irrespective of tariff type. The chart will therefore reflect a mixture of the costs to supply dual fuel and single fuel customers. As such, the bill breakdown is an approximation – values may differ, for example, if gas-only customers use more gas than those customers who are also supplied with electricity.

The data presented is based on the latest available Consolidated Segmental Statements (CSS). It may differ from the data in the suppliers externally published CSS. This is because we have made some adjustments to the way exceptional items are reported 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. 

close

Chart

Javascript is required to render chart Breakdown of an electricity bill.

Source: Companies’ consolidated segmental statements.

Information correct as of: August 2019

This chart shows an estimate of the different costs that make up an average electricity bill for a typical domestic customer of the six large suppliers. It is based on reported data from the six large suppliers’ annual Consolidated Segmental Statements.

Click the ‘more information’ tab above for information on our methodology.

For information on supplier prices and profits, please see our page Understanding the profits of the large energy suppliers.

Policy Areas:

  • Electricity - retail markets

Data Table

Breakdown of an electricity bill
Annual costPercentage
Wholesale costs32.32%
Network costs23.15%
Operating costs17.34%
Environmental and social obligation costs20.44%
VAT4.76%
Supplier pre-tax margin0.73%
Other direct costs1.25%

More Information

Methodology

To estimate the breakdown of an average electricity bill, we:

  1. Took the sum of each category of cost (e.g. wholesale, network etc) and the pre-tax supply margin reported by the suppliers for electricity.
  2. Divided the electricity sum by the total number of customers and added VAT at 5%.

Please note that chart calculations are drawn from suppliers’ reported total costs and total customer numbers, irrespective of tariff type. The chart will therefore reflect a mixture of the costs to supply dual fuel and single fuel customers. As such, the bill breakdown is an approximation – values may differ, for example, if electricity-only customers use more electricity than those customers who are also supplied with gas.

The data presented is based on the latest available Consolidated Segmental Statements (CSS). It may differ from the data in the suppliers externally published CSS. This is because we have made some adjustments to the way exceptional items are reported 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. 

close

Chart

Javascript is required to render chart Breakdown of a dual fuel bill.

Source: Companies’ consolidated segmental statements.

Information correct as of: August 2019

This chart shows an estimate of the different costs that make up an average dual fuel bill for a typical domestic customer of the six large suppliers. It is based on reported data from the six large suppliers’ annual Consolidated Segmental Statements.

Click the ‘more information’ tab above for information on our methodology.

For information on supplier prices and profits, please see our page Understanding the profits of the large energy suppliers.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of a dual fuel bill
Annual costPercentage
Wholesale costs37.59%
Network costs23.77%
Operating costs18.35%
Environmental and social obligation costs11.34%
VAT4.76%
Supplier pre-tax margin2.82%
Other direct costs1.37%

More Information

Methodology

To estimate the breakdown of an average gas and electricity bill, we:

  1. Took the sum of each category of cost (e.g. wholesale, network etc) and the pre-tax supply margin reported by the suppliers for gas. Did the same for electricity.
  2. Divided the gas sum by the total number of customers and added VAT at 5%. Did the same for electricity.
  3. Added together the resulting two figures to get a combined estimate of the overall cost of a dual fuel bill.

Please note that chart calculations are drawn from suppliers’ reported total costs and total customer numbers, irrespective of tariff type. They will therefore reflect a mixture of the costs to supply dual fuel and single fuel customers. As such, the dual fuel breakdown is an approximation – values may differ, for example, if electricity-only customers use more electricity than those customers who are also supplied with gas.

The data presented is based on the latest available Consolidated Segmental Statements (CSS). It may differ from the data in the suppliers externally published CSS. This is because we have made some adjustments to the way exceptional items are reported 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. 

close

Chart tips: Click on titles in a chart legend to switch data series on and off. View and sort chart numbers using the chart’s ‘data table’ tab, or download data in a variety of formats including images using the menu buttonmenu button