Sustainability Report Assurance & ESG Assurance

Through interviews, site or remote visits and evidence testing, we trace reported figures and claims back to source data and assess where the risk of material misstatement sits. [Timescale]

You receive an independent assurance statement for publication in your sustainability report, setting out the scope, the standard used, the level of assurance and our conclusion, plus a confidential management report with our findings and recommendations.

Limited assurance uses fewer procedures and concludes that nothing has come to the provider's attention to suggest the information is materially misstated. Reasonable assurance involves more extensive testing and gives a positive opinion, similar to a financial audit.

Yes. Companies in scope of CSRD must have their sustainability statement independently assured, at limited assurance level. UK groups can be brought into scope through their EU operations, so it is worth checking your position early.

UK SRS S1 and S2, published in February 2026, are the UK's versions of the ISSB standards. Under the FCA's rules, companies in scope report against them on a comply or explain basis for periods beginning on or after 1 January 2027, and must state whether their disclosures have been independently assured. Assurance itself is not yet mandatory, but investors increasingly look for it.

ISAE 3000 (Revised) is the international standard for assurance engagements on information other than historical financial statements. It is the most widely used standard for sustainability assurance today.

ISSA 5000 is the IAASB's global standard written specifically for sustainability assurance. The FRC has issued a UK version, ISSA (UK) 5000, which applies to periods beginning on or after 15 December 2026.

The CSRD test for which topics you must report. Impact materiality looks at how your business affects people and the environment. Financial materiality looks at how sustainability issues affect your business. A topic is material if it matters from either view. For help carrying out the assessment itself, see our materiality assessments service.

Anything with clear reporting criteria: a full sustainability report, selected ESG KPIs, Scope 1, 2 and 3 greenhouse gas emissions, climate disclosures, targets and supply chain data.

It depends on the scope, the level of assurance and how ready your data is. We agree both after a short scoping call, so you have a clear proposal before any work starts.

It is not required, but it is recommended for first-time assurance. A readiness review finds gaps in data, controls and evidence before the formal engagement, which reduces the risk of a qualified conclusion. See our gap analysis and maturity assessment service.

Not at the same time. To protect impartiality, Bureau Veritas does not provide advisory and assurance to the same client simultaneously. If you need help preparing your report, see our sustainability report advisory service.

Both audit firms and independent assurance providers. ISSA 5000 was written for any qualified assurance practitioner, not only accountants, provided they meet its ethics, independence and quality management requirements. When choosing a provider, look for independence from your reporting, experience in your sector and technical knowledge of the data being assured.