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ESG Assurance & Certification Services | BRSR Core CA
ESG Services

ESG Assurance and Certification
Making Sustainability Data Verifiable

Independent ESG assurance and certification — BRSR Core assessment readiness, GHG verification, limited and reasonable assurance engagements, and the traceability and controls a verifier will actually test.

Part of our ESG practice: ESG Audit ESG Accounting ESG Reporting Frameworks ESG Regulatory Landscape

Overview

What Is ESG Assurance?

Every sustainability report published before verification became compulsory shared one weakness: nobody had tested the numbers. Companies reported emissions, water consumption and diversity data prepared internally, reviewed internally and published without external examination. The disclosures were often accurate. They were not, in any formal sense, reliable.

That is the gap ESG assurance closes, and closing it is harder than it sounds. Financial statements rest on a double-entry system, a documented accounting framework and decades of control design. Sustainability data usually rests on a spreadsheet compiled by someone in the operations team from readings taken by somebody else. Making that assurable is not a reporting exercise — it is a systems build.

ESG assurance is an independent examination of reported sustainability information, resulting in a formal conclusion on whether that information is fairly stated. It applies the same conceptual architecture as a financial audit — an assurance standard, a suitable criteria framework, evidence gathering, materiality, and an opinion — to non-financial data. A limited assurance engagement produces a negative conclusion with fewer procedures; a reasonable assurance engagement involves substantially more work and produces a positive conclusion. India set the higher, reasonable-assurance bar for BRSR Core.

N D Savla & Associates works with companies across Mumbai, Navi Mumbai, Thane and Goa on ESG assurance and certification readiness. We assess where the reported figures come from, build the traceability and controls a verifier will test, help design methodology documentation that stands up to sampling, and manage the engagement itself. Where the company is entering the BRSR Core perimeter for the first time, we start in the year before the reporting year.

The engagement is performed under a recognised assurance standard — internationally ISAE 3000 for general assurance and ISAE 3410 for greenhouse gas statements specifically, with Indian practitioners applying equivalent standards issued by the profession. A SEBI circular of 28 March 2025 permitted assessment as an alternative to assurance for some companies, which eased the position without removing the underlying need for defensible data, a distinction our Role of Professionals in ESG page covers in more depth.

Scope of the Engagement

What Does an ESG Assurance Engagement Actually Examine?

The verifier is not testing whether the company performs well. They are testing whether what the company says about its performance is supportable — and companies preparing for a first engagement frequently prepare for the wrong question:

Documented Methodology

Whether a documented methodology exists for each reported indicator, and whether it was applied consistently across the period.

Traceability to Source

Whether the reported figure can be traced back through the calculation to an original source document — a meter reading, invoice, payroll record, or disposal manifest.

Emission Factor Selection

Which emission factors were used, from which published source, at which version, and who approved the selection.

Reporting Boundary

Whether the reporting boundary is defined and applied consistently — which sites, which entities, which operational control assumptions.

Segregation of Duties

Whether there is segregation between the person who prepares the number and the person who reviews it.

Estimates & Restatements

Whether estimates and extrapolations are disclosed as such, and whether prior-period figures have been restated on a documented basis.

The single most common finding in a first engagement is not an incorrect number. It is a number that may well be correct but cannot be demonstrated to be, because the working file was overwritten, the source data lives in an operator's notebook, or the person who prepared it has left.
ESG AttributeWhat Is Typically Hardest to Evidence
Greenhouse gas emissionsConversion of fuel and electricity data into CO₂ equivalent, and version control over emission factors
WaterDisaggregation by source where the site is metered at a single point
WasteCategorised records held by third-party handlers rather than the company
EnergyReconciliation between purchased units, generated units and consumption records
Gender diversityConsistency of employee category definitions across locations and payroll systems
WagesDemonstrating minimum wage compliance across contract labour engaged through intermediaries
Inclusive developmentSourcing and procurement data from smaller and marginalised suppliers
Fairness with customers & suppliersComplaint and grievance records maintained outside any central system
Openness of businessConcentration data on purchases and sales requiring counterparty classification

Our Services

How Do You Prepare for ESG Assurance — Step by Step?

Our preparation practice follows a structured nine-step workflow, built around one principle: readiness starts in the year before the reporting year, not in the reporting year itself.

01

Confirm the Perimeter Year and Work Backwards

Check the applicable SEBI circular for your cohort and the standard that applies to your reporting year. A company entering for FY 2026-27 needed systems operating through FY 2025-26 so a full year of controlled data exists when fieldwork begins.
02

Define and Fix the Reporting Boundary

Which legal entities, which sites, which joint arrangements, and on what basis — operational control, financial control or equity share. Boundary changes mid-period are among the hardest things to explain to a verifier, and the boundary must reconcile with how ESG accounting consolidates the underlying data.
03

Document the Methodology for Every Indicator

For each Core attribute: what is measured, how it is calculated, which conversion factors and published source, what estimates are used and why, and who owns the number. This document is the first thing a verifier asks for and the thing most companies do not have.
04

Establish Traceability From Figure to Source

Every reported number should be walkable back to a meter reading, invoice, manifest, payroll extract or contract, by someone who did not prepare it. If the calculation lives only in one person's spreadsheet, it is not traceable.
05

Put Controls Around the Data

Segregation between preparer and reviewer, approval of emission factor selection, version control on working files, evidence retention, and a documented review before publication — the same discipline as internal financial controls, applied to sustainability data.
Same discipline as ICFR / IFC
06

Run a Dry Run Before the Real Engagement

An internal review that mimics the verifier's approach — select a sample, walk it back, and see whether the evidence supports it. Findings from a dry run cost a fraction of findings raised during the actual engagement, when there is no time to remediate.
07

Appoint the Provider, Checking Independence Carefully

The provider must have the technical competence and must be free of conflicts with the entity and its group — a constraint that catches groups who assume their statutory auditor will simply extend into ESG. The audit committee should record its independence assessment, and appointment should happen early enough that scoping precedes year end.
08

Manage the Engagement and Close the Findings

Respond to information requests with source documents rather than summaries, resolve methodology differences early, and track every finding to a remediation owner. Findings that recur across two cycles are read as a control weakness rather than an isolated error.
09

Certification, as Distinct From Assurance

Certification confirms a management system conforms to a published standard — ISO 14001 for environmental management, ISO 50001 for energy, ISO 45001 for occupational health and safety, ISO 14064 for greenhouse gas quantification. A certificate does not satisfy a BRSR Core assurance requirement, though the systems discipline it imposes is genuinely useful preparation.

Why N D Savla & Associates

Why Choose N D Savla & Associates for ESG Assurance?

We prepare you for the engagement

The value is in the traceability, methodology and controls built before fieldwork — the underlying data infrastructure, which is where first-time engagements fail.

Assurance discipline from audit practice

Testing a sample, tracing it to source and forming a conclusion on the evidence is what our audit practice does across every engagement, applied to ESG data.

We flag the independence problem early

Independence conditions exclude relationships companies do not anticipate. We identify the constraint so the audit committee is not reworking its appointment two months before year end.

Honest about certification

We will tell you when a certification is worth having for operational or commercial reasons, and when it is being sold as a substitute for something it cannot replace.

Six offices across Maharashtra and Goa

Andheri, Charni Road, Vashi, Thane, New Panvel and Panaji. Assurance evidence sits at operating sites, and the ability to walk a plant with the people who record the readings matters.

Broader Practice

Our Broader ESG and Assurance Services

ESG assurance readiness draws on capability across several parts of our practice:

ESG AuditIndependent examination and testing of reported ESG figures against source evidence.
ESG AccountingBuilding the systems that consolidate sustainability data into assurable figures.
ESG Reporting FrameworksBRSR, BRSR Core and international frameworks compared and applied.
ESG Regulatory LandscapeSEBI circulars and the evolving Indian ESG compliance calendar.
Role of Professionals in ESGWho can provide assurance, and the independence rules that apply.
Internal Audit ServicesControl testing discipline that underpins a defensible assurance file.
ICFR Audit & IFC SupportInternal financial controls work that mirrors ESG control design.
Risk Control MatrixDocumented control frameworks for sustainability and financial data alike.

Frequently Asked Questions

Common Questions on ESG Assurance

What is the difference between limited assurance and reasonable assurance?
The difference is the depth of work and the form of the conclusion. Under limited assurance the practitioner performs fewer procedures and expresses a negative conclusion — that nothing has come to attention suggesting the information is materially misstated. Under reasonable assurance the practitioner gathers sufficient appropriate evidence to express a positive conclusion that the information is fairly stated. Reasonable assurance costs more, takes longer and demands far stronger underlying controls. India set the higher bar for BRSR Core, stricter than the limited assurance initially required under the European regime.
Who is permitted to provide BRSR Core assurance?
The framework does not restrict the engagement to a single profession, but it does impose independence conditions. The provider must have the necessary expertise and must not have any conflict of interest with the listed entity — which in practice excludes a provider that also supplies the entity or its group with services that would compromise objectivity, including in many cases the statutory auditor. The audit committee is responsible for satisfying itself as to the provider's independence, and that assessment should be documented rather than assumed. Our Role of Professionals in ESG page covers this in detail.
What data causes the most problems in an ESG assurance engagement?
Greenhouse gas emissions, water and waste, consistently. Emissions require fuel and electricity consumption to be converted into carbon dioxide equivalent using documented emission factors, and companies often cannot show which factor version was applied or who approved it. Water is frequently metered at a single point rather than by source. Waste records are often maintained by contractors whose documentation was never designed to be sampled.
How long does it take to become ready for ESG assurance?
For a company entering the perimeter for the first time, six to twelve months is realistic. The reporting format itself takes weeks; building the measurement systems, establishing traceability from the reported number back to a source document, documenting methodology and putting controls in place is what consumes the time. Companies that begin in the reporting year rather than the year before generally find the first engagement produces qualifications or a large volume of adjustments.
Is ESG certification the same as ESG assurance?
No. Assurance is an opinion on whether reported information is fairly stated, given by a practitioner applying an assurance standard. Certification is confirmation that a management system or a product meets a defined standard — ISO 14001, ISO 45001, ISO 50001. Certification demonstrates that a system exists and functions; assurance addresses whether the numbers reported from it are right. Companies frequently need both, for different reasons.

Entering the BRSR Core perimeter soon?

Talk to our ESG assurance team — traceability design, methodology documentation, controls, independence checks and engagement management, from Mumbai, Navi Mumbai, Thane and Goa.

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