Beyond the Boardroom: How India's ESG Mandate Is Quietly Rewriting the Rules for Millions of MSMEs

For four years, ESG reporting in India has largely been a listed-company problem. A firm compiled its own emissions, water use, and diversity numbers, filed its Business Responsibility and Sustainability Report (BRSR), and moved on. In 2026, that boundary is dissolving. The Securities and Exchange Board of India (SEBI) has shifted its BRSR Core framework from voluntary disclosure to a strictly enforced assurance regime, and the center of gravity is moving from the boardroom to the supply chain. Large listed companies are now expected to account not just for their own operations, but for the environmental and social performance of the suppliers and customers who sit outside their four walls.

That single shift is quietly becoming one of the most consequential ESG stories in Asia this year, not because of what it asks of India's largest corporations, but because of what it exposes about the millions of small and mid-sized businesses sitting underneath them.

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From Company Books to Supply Chains: What Changed

SEBI introduced BRSR in 2021 for the top 1,000 listed companies, then layered on BRSR Core in 2023: a tighter set of roughly 30 KPIs across nine attributes, covering emissions, water, waste, energy, wages, and gender diversity, among others, all subject to external assurance rather than plain self-reporting.

The Assurance Ladder

The rollout has always been phased by company size, and the ladder has been climbing steadily upward each year. Reasonable assurance on the nine BRSR Core attributes applied first to the top 150 listed entities from FY 2023-24, expanded to the top 250 from FY 2024-25, reached the top 500 in FY 2025-26, and is scheduled to cover the full top 1,000 by FY 2026-27. Each step down that ladder pulls in a wider, less resourced band of Indian corporates, many of whom are now facing ESG assurance requirements for the first time.

The newer and more disruptive layer sits on top of that ladder: value chain disclosure. From FY 2024-25, the top 250 listed companies have had to report BRSR Core data for their "Significant Value Chain Partners": suppliers and customers who individually account for 2% or more of purchases or sales, or who together make up 75% of aggregate purchase and sales value. In effect, a listed company's ESG score is no longer just its own; it inherits the sustainability performance of its supplier base, whether or not that supplier ever intended to be part of a regulatory disclosure regime.

SEBI eased the timeline for mandatory value-chain assurance in March 2025, moving it back onto a comply-or-explain footing rather than an outright deadline. But every industry tracker following the rule change describes the pause the same way: a delay in enforcement, not a change in direction. The infrastructure top companies are being asked to build now is infrastructure they will need regardless of exactly which fiscal year the assurance requirement becomes binding.

The Readiness Gap Hiding Beneath the Glide Path

The regulatory glide path is precise. The operational reality underneath it is not. Large Tier-1 suppliers to listed companies often already have certifications and formal environmental, health, and safety systems. But India's supply chains run many tiers deep, and the further down you go, the thinner the paperwork gets. Deeper-tier vendors frequently operate with minimal documentation, informal governance, and little structured measurement of energy, water, or emissions at all.

Inside the Blind Spot

One estimate making the rounds among sustainability practitioners this year puts a number on that blind spot: in a typical large Indian manufacturer's supply chain, only around 3% of the network is actively measured, leaving the vast majority of tier-3 and tier-4 suppliers effectively invisible to the reporting company sitting above them. Practitioners point to clusters like Kolhapur's foundry belt in Maharashtra as a working illustration of the problem: a dense network of small, specialized units that keep large manufacturers running, operating with the kind of informal recordkeeping and limited engineering capacity that make audit-grade ESG data genuinely hard to produce, not just unwilling to produce.

That is not a small or isolated corner of the economy. India counts more than 140 major industrial clusters, some of which account for as much as 80% of national output in a specific product category, and these clusters are exactly the deep-tier supply base that value chain disclosure is now reaching toward. Collectively, India's MSME sector emitted an estimated 135 million tonnes of CO2 equivalent in 2022, largely a byproduct of continued reliance on fossil fuels in small-scale manufacturing, which gives a sense of the scale of the data, and the emissions, sitting inside that blind spot.

The Declaration Trap

The mismatch cuts both ways. Indian corporations asking for supplier data often don't yet know precisely what to ask for or how to verify it once it arrives. MSMEs asked to supply it often don't have the systems to produce audit-grade numbers in the first place. What fills the gap today is the "declaration": a supplier simply signs a form attesting to compliance. It is a reasonable stopgap and a fragile one: declarations rely on memory rather than verified records, carry no evidence trail back to the underlying activity, and tend to collapse the moment an assurance provider actually asks for source documentation. Under reasonable assurance, that weakness stops being theoretical and starts showing up directly in the audit trail of the listed company at the top of the chain.

A Sector Already Under Pressure From More Than One Direction

BRSR Core is not the only force pushing India's MSMEs toward better sustainability data, which is part of why the trend is likely to stick rather than fade once enforcement timelines shift again. The European Union's Carbon Border Adjustment Mechanism, which begins imposing carbon costs on carbon-intensive imports including Indian steel and textiles in 2026, adds a second, independent commercial reason for export-linked MSMEs to measure and report emissions accurately. Climate volatility adds a third: Cyclone Michaung in 2023 alone disrupted roughly 4,800 MSME units in Tamil Nadu, with losses estimated near $360 million, a reminder that the same small manufacturers now being asked for ESG data are also among the most exposed to the physical risks that data is meant to track.

Why This Is Becoming a Commercial Filter, Not Just a Compliance Exercise

The practical effect is that ESG readiness is turning into a procurement criterion. Large buyers are beginning to treat supplier sustainability data the way they once treated quality certifications or delivery reliability, as a condition of doing business, not a courtesy. Surveys of global procurement leaders this year found a wide majority now factor ESG performance into sourcing decisions, even as a similarly large share admit that finding suppliers who can actually produce credible sustainability data remains difficult. Scope 3 emissions, the indirect emissions sitting in a company's supply chain rather than its own operations, typically make up 70 to 90% of a company's total carbon footprint, which is precisely why buyers are now looking past their own factory gates.

Who Is Getting It Right

Some of India's largest corporations are already treating supplier engagement as infrastructure rather than a checkbox. Tata Motors partnered with Tata Consultancy Services in late 2025 to build Prakriti, a platform that digitizes ESG data collection and automates sustainability reporting across its manufacturing plants and wider value chain, explicitly framed as part of a longer-term decarbonization commitment rather than a one-off compliance project. The wider Tata Sustainability Group describes its approach to supplier ESG the same way: less about audits and more about capability building and knowledge sharing with value chain partners over time. At the ET Edge Supply Chain Management Fest 2026, ITC and Hindustan Zinc were recognized for sustainable procurement practices, and Tata Steel for supplier relationship management, signaling that Indian industry bodies are now actively benchmarking this kind of supplier engagement rather than treating it as a niche sustainability function.

The Price of Readiness, and the Tools Already on the Shelf

None of this is free. Cost estimates for building even a baseline ESG data and governance system (readiness assessments, data tracking tools, and policy documentation) are becoming a real budget line for MSMEs in 2026-27, not an afterthought bolted onto compliance. For MSMEs, that creates a genuine strategic choice rather than a purely defensive one. An MSME that can hand a corporate buyer clean, verifiable emissions and labor data becomes easier to retain and easier to onboard for new contracts. One that cannot risk quietly losing preferred-vendor status to a competitor who can, regardless of price or product quality.

What's less widely understood is that India already has a partial toolkit for closing this gap, if the pieces get connected. The government's ZED (Zero Defect, Zero Effect) certification scheme offers MSMEs graded sustainability certification with subsidies for the certification and technology-upgrade costs involved. The RAMP scheme and the MSE Cluster Development Programme fund shared infrastructure and cleaner technology at the cluster level, which matters given how concentrated MSME production already is. SIDBI channels concessional and multilateral credit specifically toward energy efficiency and cleaner production for small enterprises. And under Section 135 of the Companies Act, large companies already sit on a legally ring-fenced CSR budget, equal to 2% of average net profit, that can be, and increasingly is being, directed toward exactly this kind of supplier-facing capacity building rather than one-off donations. The tools exist in fragments across government schemes, corporate CSR budgets, and private capacity-building programs; what is missing in most cases is a deliberate bridge connecting a listed company's value chain disclosure obligation to its own CSR spend and to the public schemes MSMEs are technically already eligible for.

What This Means for India, and the Region

India is not alone in pushing disclosure obligations down the supply chain; the EU's Corporate Sustainability Reporting Directive is doing something structurally similar for companies operating in or selling into Europe, and Southeast Asian regulators are watching both frameworks closely as they design their own rules. But India's version is distinctive because of the sheer scale of its informal and semi-formal manufacturing base sitting underneath a relatively small set of listed anchor companies. How India resolves the gap between what regulators are demanding and what its MSME ecosystem can currently deliver will likely become a reference case for other emerging Asian markets facing the same math: a handful of large, reporting-ready companies sitting atop a much larger base of suppliers that are not.

Looking Ahead

That gap is also where a real opportunity sits: for ESG data and assurance providers building tools suited to low-digitization suppliers, for CSR and capacity-building programs willing to treat supplier readiness as a value chain investment rather than a compliance cost, and for MSMEs themselves who move early enough to turn a regulatory requirement into a competitive edge. FY 2025-26 is being described across the industry not as the year value chain reporting arrives in finished form, but as the year the underlying systems either get built or don't. Companies, and their suppliers, that treat it as the latter are the ones likely to be caught short when assurance requirements tighten further, as the trajectory of the last three years suggests they will.

Sources

Maheshwari & Co. - "BRSR Core ESG Disclosures: SEBI Rules Explained"

ESG360.in - "BRSR Core & Value Chain ESG: Why FY 2025-26 Is a Turning Point for Indian Companies"

Cyril Amarchand Blogs - "SEBI's ESG Disclosure Mandates: Unveiling the Value Chain"

Glocert International - "BRSR Core Assurance Readiness Guide for Indian Companies"

Beacon Filing - "BRSR & ESG Reporting India - SEBI Compliance Guide"

EHSSaral - "MSME Supply Chains & BRSR 2026: Where Compliance Breaks"

ESGNews.earth - "Why True Decarbonization Must Fix Supply Chains"

EcoVadis - "What is Supply Chain Sustainability: Key Trends in 2026"

ESGSaathi - "ESG Compliance Cost for MSMEs in India: What to Budget For in 2026-27"

Insights on India - "Roadmap for Green Transition of MSMEs"

PHD Chamber of Commerce and Industry - "How MSMEs Can Lead India's Green Transition: Practical Sustainability Roadmap"

Catch Foundation - "CSR Under Section 135: A Complete Practical Guide"

Tata Consultancy Services - "TCS Partners with Tata Motors to Power Future-Ready Sustainability Reporting"

Tata Sustainability Group - "Supply Chain Sustainability"

The Wire / ET Edge - "ET Edge SCM Fest 2026: India's Supply Chains Must Be Rebuilt for Resilience"

EICTA Consortium, IIT Kanpur - "Sustainable Supply Chain and ESG in 2026: Build a Carbon-Responsible Strategy"

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