Sustainability Report Assurance

ISAE 3000 is the international standard for assurance engagements on subject matter other than financial information, and is the most common framework for providing assurance on sustainability reports. It is not a certification or a financial audit: its output is an assurance statement prepared against defined criteria.

The aim is to provide independent assurance that the disclosures in the sustainability report conform to the reporting framework applied and are well founded.

• Publicly listed companies publishing a sustainability report
• Groups within scope of corporate sustainability reporting
• Businesses providing assurance at investor request
• Companies using sustainability-linked finance
• Senior management required to present assurance to the board

• Accepting the assurance engagement and assessing independence
• The assurance scope: which disclosures, which period
• Determining the criteria and assessing their suitability
• Agreeing the assurance level: limited or reasonable
• Setting the materiality threshold
• Risk assessment and planning of procedures
• Examining internal controls and the data flow
• Indicator-level testing and recalculation
• Separating the responsibilities of the organisation and the assurance provider
• Drawing up the assurance statement and publishing it in the report

• ISAE 3000
• ISAE 3410 (greenhouse gas statements)
• GRI Standards
• ESRS
• IFRS S1 / S2

• ISAE 3000
• ISAE 3410 (greenhouse gas statements)
• GRI Standards
• ESRS
• IFRS S1 / S2

1. 1Engagement Acceptance and ScopeIt is agreed in writing which data will be assessed, against which reporting framework and at what level of assurance.
2. 2Establishing the CriteriaThe reporting framework applied (GRI, ESRS, IFRS S1/S2) and the organisation's own calculation methodology are established as the criteria.
3. 3Risk Assessment and MaterialityIndicators carrying a risk of misstatement are identified; the materiality threshold and the extent of sampling are set accordingly.
4. 4Examination of Internal ControlsThe data collection process, calculation controls and approval mechanisms are examined; traceability of the data back to source is tested.
5. 5Indicator-level TestingFor the selected indicators, recalculation, checking of source documents and analytical procedures are applied.
6. 6Handling of FindingsErrors identified and unsupported disclosures are communicated to the organisation; the report is corrected.
7. 7Assurance StatementAn assurance statement worded in line with the chosen level of assurance is issued and published in the report.

Assurance engagements are carried out at either limited or reasonable assurance level. In practice most sustainability reports are published with limited assurance, while regulation foresees a gradual move to reasonable assurance. The level is stated explicitly in the wording of the statement, and the two levels are not interchangeable.

• Details of the assurance provider and the team
• Indicators covered by the assurance and the period
• Reporting framework applied and the criteria
• Assurance standard applied and the level of assurance
• Summary of the procedures performed
• The division of responsibilities between the organisation and the assurance provider
• The assurance conclusion (statement)
• Disclosures excluded from the scope

ISAE 3000 assurance is not a certification and does not produce an accredited certificate; the output is an assurance statement. Assurance is valid only for the disclosures and period brought into scope. It also does not mean the organisation's sustainability performance is good; it assesses whether the reported information is presented in conformity with the criteria. Limited assurance covers a markedly narrower examination than reasonable assurance.

Greenhouse gas verification and validation activities are accredited under ISO 14065; the verification itself is performed to ISO 14064-3 and the competence of verification personnel is defined by ISO 14066. Assurance engagements, by contrast, are governed by assurance standards such as ISAE 3000 and do not fall within accredited certification. In both frameworks the impartiality rule is decisive: the party that performs the calculation cannot verify that same calculation. EUROLAB holds internationally recognised accreditation from accreditation bodies that are signatories to the ILAC and IAF mutual recognition arrangements; which verifications can be offered within accredited scope is confirmed in writing at the quotation stage.

• ESG Data Assurance
• CBAM/SKDM
• Renewable Energy
• Green Bond Verification