SUSTAINABILITY
IMPROVING AUDIT CONFIDENCE When finance teams are preparing for a statutory audit, they need to be able to navigate the structural progression from limited assurance, a moderate level or confidence with a negative-from conclusion, to reasonable assurance, or high levels of confidence through extensive testing and positive-form opinion. Many organisations are also progressing their rate of ESG Maturity – how deeply a company embeds ESG factors into its core business strategy – but not as fast as many would like. In fact, according to KPMG’ s 2025 ESG Assurance Maturity Index, 76 % of companies remain in the early or mid stages of ESG maturity – but the same research found that 60 % of firms adopting ESG assurance expect greater market share, while 54 % predict improved profitability. Initial regulatory phases begin with limited assurance – where independent auditors perform high-level analytical reviews and management inquiries to issue negative assurance statements that confirm that no incorrect statements have been identified. But as reporting standards increase – with national regulators soon having the independent authority to mandate reasonable assurance – auditors will need to perform rigorous operational verification.
Reasonable assurance asks external auditors to evaluate internal control operating effectiveness, perform on site verification and conduct extensive testing on datasets. And this higher-level reporting comes with a high-level price tag. A few years ago, the Centre for European Policy Studies’ s 2022‘ Cost-Benefit Analysis of the First Set of Draft European Sustainability Reporting Standards’ reported that annual audit costs per firm were projected to jump from € 108,000 – € 162,000( US $ 125,696 – US $ 188,545) under limited assurance to € 246,000 – € 394,000( US $ 286,309 – US $ 458,560) when obtaining reasonable assurance. Because of this, finance leaders should build strong data and control systems today to avoid expensive retrofits later to stay permanently ready for audits.
76 %
more than three quarters of companies remain in the early or mid stages of ESG maturity
Source: KPMG 2025 ESG Assurance Maturity Index
104 November 2026