Breakdown of a dual fuel bill


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%
Supplier pre-tax margin2.82%
Other direct costs1.37%

More Information


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. 

Date correct
August 2019
Policy areas