What role does third-party assurance play in CSRD compliance?

Under the Corporate Sustainability Reporting Directive (CSRD), companies are required to obtain independent third-party assurance for their sustainability disclosures. This verification process ensures that reported ESG and emissions data is accurate, consistent, and aligned with the European Sustainability Reporting Standards (ESRS). By introducing mandatory assurance, the EU aims to increase trust in sustainability reporting and ensure that disclosures hold the same level of reliability as financial reports.

Third-party assurance plays a crucial role in validating that a company’s sustainability data:

• meets regulatory and methodological requirements,
• is free from material misstatements,
• is supported by adequate internal controls and documentation,
• reflects transparent and traceable data sources across the value chain.

To prepare for assurance, companies must build robust data management processes and maintain clear audit trails. This includes implementing internal controls for data collection, applying standardized methodologies for emissions calculations, and ensuring that supplier data and system boundaries are properly documented.

How Sustamize supports the assurance process

Sustamize helps companies streamline CSRD preparation and simplify the assurance workflow by providing:

• verified, high-resolution CO₂e data aligned with ISO 14067 and the GHG Protocol,
• automated PCF and Scope 3 calculation tools that reduce manual errors,
• standardized data structures designed for auditability,
• clear documentation and traceability to support external verification.

By centralizing emissions data and applying consistent methodologies, sustamize enables businesses to deliver audit-ready sustainability disclosures and navigate the third-party assurance process with greater confidence and efficiency.

Want to simplify third-party assurance for CSRD?

Contact our team or request access to sustamize’s data and reporting tools to build accurate, transparent, and verification-ready sustainability disclosures.