Sustainability reporting & assurance

A sustainable strategy is good business practice

Why ESG assurance matters

Sustainability reporting requirements are evolving rapidly. The Corporate Sustainability Reporting Directive (CSRD), the Omnibus Regulation and international frameworks such as the International Sustainability Standards Board (ISSB) are raising expectations for transparent, reliable and decision-useful ESG reporting.

The value of ESG assurance extends beyond regulatory compliance.

• Build stakeholder trust by strengthening confidence in ESG data among investors, customers, lenders and regulators
• Support better decisions with reliable sustainability information that highlights risks, opportunities and areas for improvement
• Improve access to finance as ESG performance plays an increasing role in lending and investment decisions
• Strengthen supply chain relationships and reputation by providing trusted ESG data to customers, partners and other stakeholders

Assurance with attention: personal, pragmatic, and perfectly aligned with your business

We believe assurance truly adds value when it aligns with what matters to you. That’s why we combine the quality and expertise of a large international network with the personal attention and pragmatic approach of a boutique firm. You won’t get a standard solution from us, but an approach tailored to your sector, strategy, and ambitions.

• Experience with first-wave CSRD reporters
• Combination of financial audit and sustainability expertise
• International network with local delivery
• Sector-specific assurance specialists
• Readiness-to-assurance approach

Our services: assurance that goes further

CSRD assurance	ESG assurance	Pre-assurance	Training / Workshops
CSRD assurance services	Assurance on sustainability KPIs Assurance on qualitative sustainability claims EU Taxonomy assurance Green bond verification VSME assurance	DMA assurance Gap assessment Development of sustainability reports Sustainability assurance readiness Pre-assurance procedures	ESG training and workshops CSRD Training & Workshops ESG Reporting Training Sustainability Reporting Masterclass

Services related to assurance

• DMA review / assurance procedures
• Pre-assurance procedures

Non-assurance & quality services

• Sustainability assurance readiness
• ESG training and workshops
• Sustainability reporting gap assessments
• Development of sustainability reports

What to expect from an assurance engagement

A structured assurance engagement helps build confidence in your sustainability reporting and supports compliance with evolving regulatory requirements. While every engagement is tailored to your organisation, the process typically includes the following stages:

• Scoping and planning
  Define the scope of the engagement, identify reporting requirements and agree timelines, responsibilities and key focus areas.
• Readiness assessment
  Evaluate the maturity of your sustainability reporting processes, controls and data to identify gaps before formal assurance begins.
• Testing and evidence gathering
  Review relevant processes, controls and supporting documentation. Test reported data and assess whether sufficient evidence supports your disclosures.
• Findings and recommendations
  Share observations and practical recommendations to strengthen reporting processes, data quality and internal controls.
• Assurance conclusion
  Provide an independent assurance conclusion on the sustainability information within the agreed scope.

Moving forward together

Whether you are preparing for your first Corporate Sustainability Reporting Directive (CSRD) assurance engagement or seeking assurance over specific sustainability disclosures, Forvis Mazars can help you assess your readiness and support a smooth assurance process.

1. Contact us
2. Schedule a readiness assessment
3. Speak with a sustainability assurance specialist