Department for Energy Security and Net Zero

DEFRA emission factors are the United Kingdom's official greenhouse gas conversion factors for corporate climate reporting. The 2025 release was published on 10 June 2025 by the Department for Energy Security and Net Zero (DESNZ). Practitioners still refer to these as the "DEFRA factors" - a name retained from the dataset's origin at the Department for Environment, Food and Rural Affairs, before responsibility transferred to the Department for Business, Energy and Industrial Strategy (BEIS) and, in 2023, to DESNZ. UK organisations use DEFRA emission factors to meet mandatory Streamlined Energy and Carbon Reporting (SECR) obligations, complete Energy Savings Opportunity Scheme (ESOS) audits, and respond to Procurement Policy Note 06/21 carbon reduction plans for major government contracts. The dataset is also the default UK reference for voluntary disclosure under the GHG Protocol Corporate Standard, CDP climate questionnaires, TCFD-aligned reporting, and ISSB / IFRS S2 climate disclosures. The complete DEFRA 2025 dataset covers Scope 1 direct emissions from stationary and mobile combustion, Scope 2 purchased electricity on both location-based and market-based methodologies, and Scope 3 categories spanning business travel, employee commuting, freight and goods transport, waste treatment, water supply and treatment, refrigerants, and purchased materials. Factors are published with full CO₂, CH₄, and N₂O component breakdowns alongside aggregated CO₂e values, assessed on AR5 100-year Global Warming Potentials. Greentryst currently publishes 166 verified Scope 1 fuel and bioenergy factors from this release. Scope 2 electricity and Scope 3 categories will follow as each slice completes our verification workflow.