Cost breakdown of an electricity bill in Great Britain (GB) 2020

The source notes that this data is an estimate of the costs in a gas bill of an average domestic customer of the large suppliers in 2018. 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. The 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.