Sustainability Assurance

Sustainability assurance is the external, independent verification of the sustainability disclosures presented in the management report under the Corporate Sustainability Reporting Directive (CSRD) and the European Sustainability Reporting Standards (ESRS). With the transposition of the CSRD into national law, sustainability information becomes subject to a statutory assurance requirement for the first time. This requirement is aligned with the audit of the financial statements and is intended to ensure that the reported ESG data is reliable, complete and compliant with the applicable reporting standards.

The CSRD provides for a phased level of assurance. In the first phase, limited assurance is required, in which the assurance provider, through a critical review, reaches a negatively worded conclusion stating that nothing has come to their attention that would indicate non-compliance. A later transition to reasonable assurance is envisaged, which calls for a positively worded opinion with a higher degree of reliability. The engagement covers formal compliance with the ESRS, the conduct of the double materiality assessment, the selection of data points, and the digital tagging of disclosures in the ESEF format.

In Germany, the assurance may be performed by the statutory auditor, another auditor, or in future also by independent assurance services providers. For companies, the assurance requirement means that sustainability data must meet the same standards of internal control, traceability and documentation as financial data. An audit-ready preparation with clear responsibilities, documented data collection methods and a robust audit trail is therefore decisive in order to obtain an unqualified assurance conclusion and to minimise the risk of findings or greenwashing accusations.