Question

What does external assurance actually involve, and who can provide it?

External assurance is an independent verification process in which a qualified third party reviews your sustainability data, checks it against source records, interviews key personnel and issues an assurance statement confirming the reliability of the reported information. It typically runs in three phases — planning (scoping the areas and assurance level), fieldwork (document review, data sampling, interviews) and reporting (the assurance statement). For a limited assurance engagement — the standard level for EcoVadis — the full process typically takes three to six months, depending on size, complexity and the number of indicators covered.

Any independent, qualified third party with relevant sustainability-assurance expertise can provide it: specialist providers, accredited verification bodies, and mid-tier audit firms with a recognised sustainability practice — a Big Four firm is not required. The critical requirement is independence: an internal audit does not satisfy the criterion, nor does a management-consulting engagement. For KPI-level verification (e.g. confirming that 85% of employees completed ethics training), a focused, scoped verification by a qualified independent party can satisfy the relevant criteria. For Reporting questions, the top score requires assurance covering all four themes — a statement covering only GHG emissions applies only to the Environment pillar.