Organisations face mounting pressure to account for biodiversity loss, yet operational firm-level approaches remain limited. This study develops a nature-accounting workflow pairing the Impact-Weighted Accounts Framework with Global Impact Database Biodiversity Impact Data to quantify an e-commerce platform’s footprint. Revenues are mapped to input–output sectors and impacts monetised across five pathways (air pollution, climate change, land occupation, water pollution, water use). The estimated biodiversity loss equals ~16.3% of annual revenue, with ~99% arising upstream and downstream; land occupation (~40%) and climate change (~37%) dominate. We make explicit key assumptions (proxy geographies, sector mapping, Full-Chain vs. Value-Chain attribution) and provide sensitivity analyses relevant to governance and disclosure. The contribution is to show how calculative devices redirect managerial attention beyond organisational boundaries and translate biodiversity impacts into decision-useful signals for procurement, logistics, and TNFD-aligned investor communication, while clarifying boundary conditions of current metrics.