WeZero is a free carbon accounting platform for UK businesses. Enter your fuel, fleet, electricity and Scope 3 activity data and the calculator applies the latest UK Government (DESNZ) GHG conversion factors to produce your carbon footprint in tonnes of CO2e, with full calculation transparency. Results can be viewed year by year or on a multi-year master dashboard with intensity metrics and charts. Paid plans add SECR reporting with a downloadable Word narrative, a Carbon Reduction Plan aligned to PPN 006, a GHG inventory module, NHS Evergreen assessment tools and supplier engagement. A free Smart Energy tool identifies energy and carbon saving opportunities, and the Internal Carbon Fee tool models a virtual carbon fund. Training videos and an interactive walkthrough help new users get started, and the FAQ answers common questions about methodology, conversion factors and reporting standards.