CSRD Compliance: Strengthen ESG Reporting with Voluntary Assurance

Use voluntary assurance to improve ESG data quality, build trust, and prepare for CSRD compliance with stronger governance and controls.

In brief

• The EU Omnibus package has delayed Wave 2 CSRD by two years and introduced simplifications. 
• Organisations now face uncertainty while final CSRD rules are being set. 
• This is an opportunity for Organisations to prepare early for a smooth implementation of CSRD. 

The EU’s Corporate Sustainability Reporting Directive (CSRD) aims to improve the consistency and quality of ESG disclosures from large organisations. It requires limited assurance on reported data for transparency and accountability.

As businesses prepare for CSRD reporting, many face challenges with the standard and reliability of non-financial information. Unlike financial reporting, typically supported by mature governance structures and controls, ESG data can be fragmented, inconsistent and dispersed across systems and geographies with limited oversight and standardisation.

The EU Omnibus package offers a two-year preparation window, which is a valuable opportunity to be used wisely. Companies can develop comprehensive implementation plans to strengthen internal controls, align data sources, and build governance around non-financial metrics. Voluntary assurance can help identify weaknesses, validate reporting approaches, and build confidence in disclosures.

Challenges faced by Organisations

Under the CSRD, companies currently need to disclose over 1,000 sustainability-related data points, with approximately 30% of these being quantitative. EFRAG’S revised ESRS draft (proposed July 2025), could cut reportable items by up to 57%, mainly in qualitative areas. Despite this, organisations will still face hundreds of disclosures making strong data systems essential. 

Organisations working on CSRD reporting often struggle with data gaps. This is especially true for those that have made many acquisitions. Different entities may use separate systems and standards, which creates inconsistencies. These issues make it harder to produce a reliable sustainability report that meets regulatory and stakeholder expectations.

Moreover, the resources dedicated to sustainability reporting can often be limited, both at a group level and within individual entities. Parent companies might lack sufficient governance structures surrounding sustainability, while subsidiaries may not have the same level of infrastructure or support as the parent company. There’s a critical need to train staff so they can collect complete and accurate data. Without this, gaps in governance and data quality may emerge. Limited resources increase the risk of errors and non-compliance.

Implementing controls and setting up a strong sign-off process is a key step in the context of preparing for CSRD reporting. ESG teams can use finance-type controls that already exist in their financial reporting process. A good starting point is to look at the organisation’s current controls. This helps assess whether established processes for data review and approval can apply to sustainability reporting. Parent companies may already have protocols in place, but subsidiaries also need to meet local rules. Both need to be considered to keep reporting consistent across the group. 

To address these challenges, organisations must prioritise the development of a cohesive implementation plan that encompasses both the parent company and its subsidiaries, specifically tailored to meet CSRD reporting requirements. It should also include other ESG reporting frameworks that companies may be required to implement or wish to consider in their sustainability journey.

The benefits of voluntary assurance

Voluntary sustainability assurance over selected metrics can provide a useful step as a company prepares for CSRD reporting with many associated benefits including: 

Confidence in data: Clear review processes, approval protocols, and data controls are the foundations for credible reporting. Independent assurance gives confidence that these structures hold, and that data stands up to scrutiny. 

Stepping stone to CSRD reporting: Companies must get limited assurance on the CSRD report that management prepares and includes in the Annual Report. Getting optional assurance on specific metrics early on gives companies a chance to get feedback and improve their processes before they have to meet all CSRD requirements. Recent benchmarking research conducted by EY, the EY CSRD Barometer 2025, revealed that in the first wave of CSRD implementation, approximately 50%¹ of companies opted for voluntary assurance in advance of their CSRD reporting compliance.

Availability of an audit trail: Before a voluntary assurance review, management needs to check if their process leaves a clear trail that can be audited. This means keeping detailed records of how data was collected, what methods were used, and what results were found. These records help assurance providers check that the data is reliable. By preparing this documentation early, management can spot and fix any issues ahead of time, making the assurance process easier.

Enhancing organisational collaboration: Voluntary assurance can help teams work better together. Through the process, colleagues will see shared challenges and useful practices, improving how data is handled. This teamwork boosts data quality and encourages learning, helping people see how their roles connect and reducing silos.

Feedback: As part of assurance, management receives feedback on gaps or weak controls. This helps improve processes and fix issues early, before formal reporting. 

Where Can Companies Start their Voluntary Assurance Journey when Preparing for CSRD reporting?

According to EY's CSRD Barometer 2025, the most reported sustainability matters as part of the Double Materiality Assessment (DMA) results include ESRS E1 Climate change, S1 Own workforce and G1 Governance. With the current draft ESRS proposals not expecting to reduce quantitative metrics, focusing on a selection of quantitative data points in these areas would be a good starting point. This will enable businesses to prioritise their voluntary assurance efforts, ensuring that they are prepared for the rigorous scrutiny that will accompany CSRD reporting compliance. 

Conclusion

Voluntary assurance helps companies get ready for CSRD reporting. It supports better data, clearer governance, and stronger documentation. It also builds trust. 

By focusing on useful data, training staff, and keeping good records, businesses can meet expectations and show their reports are solid. This work makes CSRD reporting less of a hurdle and more of a chance to improve.

Summary

The EU has given organisations more time to get ready for CSRD reporting. This extra window is a chance to improve how ESG data is collected, reviewed, and shared. Voluntary assurance helps spot weak areas early, build trust in the data, and prepare for future audits. It also encourages better teamwork and clearer processes. By focusing on strong controls, good records, and staff training, companies can make CSRD reporting smoother and more reliable.