What is sustainability assurance?
Sustainability assurance applies to a defined set of disclosures, which can include climate, water, workforce or governance information. An independent provider evaluates that information against named criteria, tests supporting records and issues a signed report stating its conclusion and assurance level. GHG verification is narrower because it focuses on a greenhouse gas statement.
Why does sustainability assurance matter to you?
Customers, investors and reporting laws can ask for it. Microsoft's 2025 supplier instructions use independent assurance as one option for total-company and service-level GHG emissions. For entities required to prepare a sustainability report under Chapter 2M of Australia's Corporations Act, ASSA 5010 requires a review of specified first-year disclosures, review of all disclosures in years two and three, and an audit of all disclosures from year four.
How does sustainability assurance work?
Set the scope before testing: entity, period, disclosures, reporting rules and assurance level. The provider selects records, checks calculations and controls, investigates differences and signs a conclusion. Check that the provider did not prepare the information or make management decisions, and that the engagement lead can show relevant assurance experience, suitable professional credentials and the recognised assurance standard they will use. If a request also mentions consultant support, compare consultant letters with independent assurance before choosing the deliverable.
What mistakes should you avoid?
- Calling advice from the disclosure preparer independent assurance.
- Not naming the entity, period, metrics or reporting rules.
- Claiming the full report was assured when the conclusion names only selected disclosures.
Is sustainability assurance limited to GHG emissions?
No. It can cover environmental, social or governance information. The signed conclusion must identify the information actually tested.
Can one assurance report cover only part of a sustainability report?
Yes. Read the scope and conclusion before sending it. Unlisted metrics, sites, periods and forward-looking statements are not covered merely because they appear beside assured information.