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 2016

This chart provides an estimate of the proportion of different costs in the dual fuel bill of an average domestic customer of the large suppliers in 2015. 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.

Policy Areas:

  • Electricity - retail markets
  • Gas - retail markets

Data Table

Breakdown of a dual fuel bill
Annual costPercentage
Wholesale costs43.43%
Network costs23.98%
Environmental and social obligation costs7.35%
Other direct costs0.63%
Operating costs15.80%
Supplier pre-tax margin4.04%

More Information


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 (CSS). It may differ from the data that can be found in the supplier’s externally published CSS. 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.

Date correct
August 2016
Policy areas