Yes. The consultant prepares your report, from the double materiality assessment to ESRS mapping and a documentation trail the auditor can follow. Your auditor independently assures the result. Raise open issues with the auditor early. Just don’t let one firm do both for the same report, because that breaks EU independence rules.
Yes, a CSRD consultant can absolutely work alongside your existing auditor. In fact, for most organizations going through CSRD compliance, having both is not just possible but genuinely useful. The two roles are distinct enough that they complement each other well, and a good CSRD consultant will actively support the audit process rather than duplicate it.
To understand why that collaboration works so well, it helps to start by clarifying what each role actually involves.
What roles do a CSRD consultant and an auditor each play?
A CSRD consultant and an auditor serve fundamentally different functions. The consultant helps you build, structure, and interpret your sustainability reporting process, while the auditor independently verifies the accuracy and completeness of what you have produced.
More specifically, a CSRD consultant — particularly one specializing in sustainability reporting — typically focuses on tasks such as conducting the double materiality assessment, mapping your disclosures to the European Sustainability Reporting Standards (ESRS), identifying gaps in your data collection, and helping your team understand what the regulation actually requires. This is strategic and operational work, carried out from within your process.
Your auditor, on the other hand, sits outside that process by design. Under the CSRD framework, companies subject to the regulation must have their sustainability information independently assured. As of 2026, this is carried out through limited assurance, meaning the assurance provider evaluates whether anything in your sustainability report is materially misstated — they do not help you build the report; they assess it once it exists.
It is worth noting that the Omnibus I reform (Directive (EU) 2026/470), which came into force in March 2026, has significantly narrowed the scope of who must comply with CSRD at all. The revised threshold requires more than 1,000 employees and more than 450 million euros in net turnover, which means approximately 80% of previously in-scope companies no longer face mandatory reporting. If your organization remains in scope, however, both roles remain highly relevant — and understanding how they work together in practice is the logical next step.
How does a CSRD consultant work alongside an existing auditor?
A CSRD consultant and your existing auditor can work together effectively as long as their responsibilities are clearly delineated. The consultant focuses on preparing and structuring your sustainability disclosures, while the auditor independently reviews and assures the final report.
In practice, the collaboration tends to be sequential rather than simultaneous. The consultant carries out the substantive work during the preparation phase — conducting the double materiality assessment, mapping relevant ESRS datapoints, and building the internal processes needed to collect and document sustainability information. Once that groundwork is complete, the auditor steps in to provide assurance.
That said, some back-and-forth between the two parties is normal and constructive. A well-prepared consultant will anticipate what the auditor will need to examine and ensure the documentation trail is clear and traceable, which means the audit proceeds more efficiently with fewer requests for additional evidence.
Direct communication between the two parties can also be valuable. If the consultant identifies an area of uncertainty during preparation — for example, a contested materiality decision or a datapoint with limited coverage — it is generally advisable to raise that with the auditor early rather than waiting for it to become a formal finding.
One question that often arises at this point is whether it is possible — or appropriate — for a single firm to handle both sides of this relationship.
Can the same firm handle both CSRD consulting and auditing?
Generally, no. The same firm should not provide both CSRD consulting and assurance on the same engagement. If a firm helps you build your sustainability report and then assures it, they are effectively reviewing their own work, which undermines the credibility of the assurance opinion.
This is not simply a matter of best practice. Audit independence requirements under EU law are designed to prevent precisely this kind of conflict. Under the revised assurance framework introduced through the Omnibus process, firms providing sustainability assurance must meet defined independence standards, and those standards are incompatible with also acting as the reporting consultant for the same client.
There is some nuance here. A large firm may have separate teams for sustainability consulting and audit assurance, with internal separation measures designed to manage independence. Whether that separation is sufficient is a question worth putting directly to the firm and, if necessary, to your audit committee.
The practical benefit of using two separate providers is that you receive genuinely independent feedback. If your consultant’s work contains gaps, the auditor will identify them — which functions as a useful quality check and gives your stakeholders greater confidence in the integrity of the final report.
With that boundary established, it becomes important to think carefully about what the consultant should actually hand over to the auditor once the preparation phase is complete.
What should a CSRD consultant share with the auditor?
A CSRD consultant should provide the auditor with the full documentation underpinning your sustainability report. This includes the methodology and outputs of your double materiality assessment, the data sources and collection processes used for each ESRS disclosure, any assumptions made where data was incomplete, and the reasoning behind materiality decisions.
The auditor’s role is to provide assurance on the report, but they can only do so effectively if they understand how the report was constructed. Without the underlying documentation, the auditor is essentially evaluating conclusions without being able to trace them back to their foundations.
A few specific areas where thorough handover documentation tends to make a meaningful difference:
- Double materiality assessment: The double materiality assessment is widely regarded as the most judgment-intensive part of CSRD preparation. The consultant should document the process clearly, including which stakeholders were consulted, how impacts and financial risks were scored, and why certain topics were included or excluded. Auditors will scrutinize this area closely.
- Data collection methodology: For each ESRS datapoint included in the report, there should be a clear record of where the data originated, who provided it, and how it was verified internally before inclusion.
- Assumptions and limitations: Where data was estimated, extrapolated, or subject to limitations, those decisions should be documented and disclosed. Auditors are not seeking perfection; they are assessing transparency and consistency.
Taken together, this documentation package gives the auditor a solid and traceable basis on which to work. A consultant who prepares it thoroughly contributes to an audit that is faster, more cost-effective, and more likely to result in a clean assurance opinion.
Of course, the quality of that handover depends heavily on when the consultant was brought in — and getting the timing right is one of the most consequential decisions you will make in this process.
When should a CSRD consultant be brought in relative to the audit?
A CSRD consultant should be engaged well before the audit begins, ideally at the outset of your reporting preparation cycle. The consultant’s work — particularly the double materiality assessment and ESRS gap analysis — must be completed before there is anything substantive for the auditor to review.
A useful way to consider the timeline is in distinct phases. The consultant delivers the greatest value during the preparation phase, which involves understanding the regulatory requirements, scoping your disclosures, collecting and structuring data, and drafting the sustainability statement. Depending on the complexity of your organization and the maturity of your existing sustainability data, this phase can span several months.
The auditor then engages during the assurance phase, typically once a near-final draft of the sustainability statement is available. Limited assurance under CSRD is not a brief process, and the auditor will require adequate time to review documentation, raise queries, and issue their opinion before your reporting deadline.
A common error is treating the audit as the final step and only involving the consultant once problems have been identified. This approach tends to create time pressure and can lead to disclosures being revised in ways that introduce inconsistencies.
It is also worth noting that the revised ESRS, adopted by the European Commission on 3 July 2026, reduce the number of mandatory datapoints by more than 60%. That represents a significant change to the scope of what must be reported, and a CSRD consultant who is current on these revisions can help you avoid over-reporting or preparing for requirements that no longer apply. Note that the revised ESRS are currently under scrutiny by the European Parliament and Council and are not yet final, so monitoring developments closely remains important.
Knowing when to bring in a consultant is only half the equation — you also need to know what to look for when choosing the right one.
How do you find a CSRD consultant who is audit-ready?
An audit-ready CSRD consultant is one who understands not only the reporting requirements but also what auditors will examine when they review the output. The key qualities to look for are deep familiarity with the ESRS, experience conducting double materiality assessments, and a demonstrable track record of producing documentation that holds up under scrutiny.
A few practical considerations when evaluating candidates:
- ESRS expertise: The consultant should be thoroughly familiar with the current version of the standards, including the revised ESRS adopted in July 2026. Given the extent of the changes introduced through the Omnibus reform and the simplified standards, engaging someone who continues to operate on outdated assumptions represents a material risk.
- Experience with double materiality assessments: This is one of the most technically demanding aspects of CSRD preparation and one of the areas auditors assess most closely. Ask specifically about the consultant’s methodology and how they have handled contested materiality decisions in previous engagements.
- Documentation discipline: Establish how they document their work. A consultant who produces clear, traceable records of methodology and data sources will make your audit significantly more straightforward. One who works informally and delivers a draft without supporting documentation will not.
- Independence awareness: A competent consultant will proactively identify any independence considerations arising from existing relationships with your audit firm, and will help you structure the engagement in a way that protects the integrity of the assurance process.
Finding someone who meets all of these criteria is not always straightforward, particularly given how rapidly the regulatory landscape has shifted. Many organizations are finding that the sustainability consultants they have worked with on other topics — such as EU Taxonomy alignment or CDP reporting — do not necessarily possess the specific CSRD and ESRS depth required for this type of work.
If you are ready to move forward, the good news is that finding the right specialist does not have to be a lengthy or uncertain process.
Ready to find the right CSRD consultant for your team?
Getting CSRD compliance right requires the right expertise at the right time, and that is exactly what we built Dazzle for. Our network of 150+ pre-screened sustainability experts includes specialists in CSRD and ESRS reporting who know how to prepare documentation that works for both your internal team and your auditor.
Whether you need someone to lead your double materiality assessment, structure your disclosures, or get your reporting process audit-ready, we can match you with the right person quickly. You can start working with a vetted CSRD consultant within 48 hours, with no lengthy procurement process or agency overhead.
If you are not yet certain what you need, that is fine too. Reach out to our team and we will help you work through it together.
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The free CSRD Evidence Register lists all 14 documents, what each costs you and where teams get stuck, from a panel with Dazzle clients PostNL and Samskip.
