ESG Audit Services — Sustainability Audit & Assurance | Nainit Savla & Associates

ESG Audit

Q: What is the difference between limited assurance and reasonable assurance in an ESG audit?

Reasonable assurance (like a financial audit) provides high confidence with extensive procedures and a positive conclusion. Limited assurance provides lower confidence with inquiry-based procedures and a negative conclusion. BRSR Core currently requires limited assurance, expected to progress to reasonable assurance.

Q: Who can provide ESG assurance in India?

SEBI specifies that BRSR Core assurance must be provided by practising Chartered Accountants or CA firms — positioning the CA profession centrally in India's ESG assurance market. Specialist ESG providers may be used for GRI or TCFD reports but SEBI BRSR Core compliance requires CA firms.

Q: What standard does an ESG audit follow?

ISAE 3000 for non-financial information assurance; ISO 14064-3 for GHG emissions verification; ICAI guidance notes on ESG assurance; and GRI Reporting Principles for GRI-aligned reports. The applicable standard is disclosed in the assurance statement.

Q: How long does an ESG audit typically take?

3 to 8 weeks depending on scope, locations, and data system maturity. Companies with robust year-round ESG data management experience shorter, smoother audits. First-year ESG audits typically take longer as data gaps are identified and resolved.

Q: Can the same CA firm that performs the financial audit also perform the ESG audit?

No regulatory prohibition exists in India's current BRSR framework, but independence considerations are relevant. Many companies engage a different firm for ESG assurance to signal independence. ICAI ethical standards on independence apply to ESG assurance engagements.

An ESG audit is an independent, structured examination of a company's sustainability data, processes, and disclosures — designed to provide credible, external verification that the ESG metrics and statements published in sustainability reports, BRSR filings, and investor communications are accurate, complete, and consistent with the underlying records. As ESG reporting matures from voluntary disclosure to regulated, assured disclosure — particularly under SEBI's BRSR Core framework — the quality, rigour, and independence of the ESG audit is becoming as important as the data being reported. We provide independent ESG audit and assurance services for listed companies, supply chain participants, and organisations seeking credible third-party validation of their sustainability performance.

BRSR Core Assurance

Third-party assurance engagement over the BRSR Core key performance indicators — mandatory for top listed companies under SEBI's expanding BRSR assurance requirements, conducted in accordance with ISAE 3000 or applicable standards.

GHG Emissions Verification

Independent verification of Scope 1, 2, and 3 greenhouse gas emissions inventories — checking emission factor selection, activity data completeness, boundary definition, and calculation accuracy against the GHG Protocol Corporate Standard.

Sustainability Report Audit

Comprehensive audit of standalone sustainability reports or integrated annual reports — verifying all material ESG disclosures against underlying source data, checking internal consistency, and assessing alignment with stated framework (GRI, TCFD, SASB).

Supply Chain ESG Audit

Supplier ESG audit for companies required to verify the sustainability practices of their supply chain — covering environmental compliance, labour standards, health and safety, and ethical sourcing at supplier facilities.

ESG Data Quality Review

Pre-assurance review of ESG data systems, collection processes, and internal controls — identifying weaknesses in data quality that would result in audit findings, enabling remediation before the formal assurance engagement.

Carbon Footprint Audit

Independent audit of the company's carbon footprint calculation — verifying boundary completeness, activity data accuracy, emission factor appropriateness, and GWP (Global Warming Potential) values used in the calculation.

ESG Audit vs Financial Audit — Key Differences

A financial audit provides an opinion on whether financial statements give a true and fair view under prescribed accounting standards — with well-established audit procedures, materiality concepts, and professional standards developed over decades. An ESG audit operates in a less mature environment — ESG frameworks are still evolving, emission factor databases are updated periodically, and ESG data collection systems in most companies are less robust than financial accounting systems. ESG audit standards (primarily ISAE 3000 for non-financial information and ISO 14064-3 for GHG verification) provide a framework, but the application requires specific sustainability expertise alongside audit skills.

As SEBI's BRSR Core mandates expand, ESG audits are becoming regulatory requirements for Indian listed companies — with ICAI and SEBI both working to establish professional standards for ESG assurance in India.

ESG Audit Process — What We Examine

Organisational boundary — whether all relevant entities and operations are included in the ESG reporting boundary
Data collection — completeness and accuracy of primary data from all operational sites
Emission factors — appropriateness and currency of emission factors used for GHG calculations
Calculation methodology — mathematical accuracy and consistent application of stated methodology
Internal controls — whether adequate controls exist to prevent errors and ensure data integrity
Disclosure completeness — whether all material ESG topics required by the chosen framework are disclosed
Year-on-year consistency — whether methodology changes between years are disclosed and restated
Qualitative disclosure accuracy — whether narrative statements are consistent with quantitative data

Frequently Asked Questions

What is the difference between limited assurance and reasonable assurance in an ESG audit?

In assurance terminology, reasonable assurance (equivalent to a financial audit opinion) provides a high level of confidence that the subject matter is free from material misstatement — the assurance provider performs extensive procedures and expresses a positive conclusion ("the data presents fairly"). Limited assurance provides a lower level of confidence — the assurance provider performs fewer, primarily inquiry and analytical procedures, and expresses a negative conclusion ("nothing has come to our attention to indicate material misstatement"). BRSR Core currently requires limited assurance from the top 150 listed companies — this is expected to progress toward reasonable assurance as ESG data quality and assurance standards mature in India.

Who can provide ESG assurance in India?

SEBI's BRSR framework specifies that the BRSR Core assurance must be provided by a Chartered Accountant (practicing CA or CA firm) — which aligns ESG assurance with the ICAI's professional ambit. SEBI issued a circular in 2023 clarifying that only ICAI members (CAs in practice) are eligible to provide BRSR Core assurance for the first phase of mandated companies. This is a significant development that positions the CA profession centrally in India's growing ESG assurance market. Some companies also engage specialist ESG assurance providers (such as the Big 4 sustainability practices or certification bodies) for their broader GRI or TCFD reports, but for SEBI BRSR Core compliance, CA firms are the mandated providers.

What standard does an ESG audit follow?

ESG audit and assurance engagements in India follow: (a) ISAE 3000 (International Standard on Assurance Engagements) for assurance over non-financial information — which provides the overarching framework for both limited and reasonable assurance engagements; (b) ISO 14064-3 for third-party verification of GHG emissions inventories specifically; and (c) ICAI's own guidance notes on ESG assurance, which ICAI has been developing in alignment with international standards. For GRI-aligned reports, the GRI Reporting Principles (accuracy, completeness, comparability, balance, timeliness) inform the assurance scope. The applicable standard is disclosed in the assurance statement accompanying the sustainability report.

How long does an ESG audit typically take?

An ESG audit or assurance engagement typically takes 3 to 8 weeks depending on the scope (limited vs reasonable assurance), the number of locations and operations covered, the maturity of the company's ESG data systems, and the quality of supporting documentation. Companies that invest in robust ESG data management systems throughout the year — with clear data owners, documented methodology, and audit-trail documentation — experience significantly shorter and smoother ESG audits. Companies beginning ESG auditing for the first time typically find the first year takes longer as data gaps and methodology issues are identified and resolved.

Can the same CA firm that performs the financial audit also perform the ESG audit?

There is no regulatory prohibition in India (as of the current SEBI BRSR framework) that prevents the statutory auditor from also providing BRSR Core assurance. However, independence and conflict of interest considerations are relevant — particularly as ESG assurance standards evolve. Many large listed companies choose to engage a different firm for ESG assurance to signal independence and avoid any actual or perceived conflict. ICAI's ethical standards on independence apply to ESG assurance engagements as they do to audit engagements, and the assurance provider must assess whether their other services to the same client impair independence before accepting an ESG assurance mandate.

ESG Audit That Builds Stakeholder Confidence

Independent ESG audit and assurance for BRSR Core, GHG verification, sustainability reports, and supply chain ESG compliance across India.

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