BRSR Core in FY 2025-26, What SEBI Now Asks of India's Top 500 Listed Companies

If you supply to a big listed company in India, your ESG numbers are slowly becoming their problem. Which means they are about to become yours.

Every year, SEBI widens the circle of companies that must get their sustainability numbers checked by an outsider. This year the circle got much bigger, and the rules of the checking changed too. If you work in ESG, finance or compliance, or you sell to a listed company, this is worth ten quiet minutes. Let me walk you through it the way I would in class.

First, what is BRSR Core

You already know the BRSR - the Business Responsibility and Sustainability Report that SEBI requires the top 1,000 listed companies to file with their annual report. The BRSR Core is a smaller, sharper sub-set of that report: a fixed set of Key Performance Indicators across 9 ESG attributes, designed so that the most important numbers can be checked independently. It deliberately includes India-relevant metrics you will not find in global frameworks, like job creation in small towns and gross wages paid to women, and it uses intensity ratios adjusted for purchasing power parity so Indian numbers can be compared globally.

The simple way to think about it. BRSR is the full report card. BRSR Core is the part of the report card that someone else now has to verify.

What changed, and who is in the net now

Two things matter this year.

One, the circle widened. The mandatory checking of BRSR Core follows a glide path by market capitalisation. It began with the top 150 listed entities in FY 2023-24, moved to the top 250 in FY 2024-25, and from FY 2025-26 - the financial year that just ended in March 2026 - it covers the top 500. In FY 2026-27 it reaches the top 1,000. If a company was sitting comfortably outside the list, this may be the year it walked in.

Two, SEBI softened how the checking happens. In March 2025, SEBI replaced the old "reasonable assurance" requirement with "assessment or assurance". Assessment is a third-party check done under standards developed by the Industry Standards Forum in consultation with SEBI - a lighter, cheaper, profession-agnostic route, created deliberately to reduce cost and effort for companies. Assurance remains the deeper audit-style option. Companies get to choose, but one of the two is now mandatory for everyone in the glide path.

There is one more rule I find genuinely elegant. Whoever checks your BRSR Core cannot also sell consulting to you or your group companies. SEBI built the wall between the checker and the coach right into the regulation, so the check stays honest.

And the suppliers? That is the value chain part

This is where it reaches beyond listed companies. SEBI wants listed companies to eventually disclose BRSR Core-style numbers for their value chain - the top upstream and downstream partners that individually make up 2% or more of the company's purchases or sales, with an option to limit coverage to 75% of purchase and sales value.

The good news, and many people missed this: SEBI deferred this by a year and made it voluntary for now. Value chain disclosures are voluntary for the top 250 listed entities from FY 2025-26, and the checking of those disclosures stays voluntary from FY 2026-27. For the first reporting year, even previous-year numbers are voluntary.

Voluntary today does not mean ignorable. When your largest customer is a listed company getting its own numbers audited, the questionnaire lands on your desk next. The smart suppliers I know are using this voluntary window to get their basic data in order before it becomes a request they cannot refuse.

What I tell my students

If you are inside a listed company, find out where you sit on the glide path and whether your board has picked an assessment or assurance provider - remember, it cannot be your consultant. If you are a supplier, treat this as your early warning: the emissions, energy, water, waste and people numbers you track loosely today are the ones someone will ask you to prove tomorrow.

And if you want to actually learn how BRSR reporting works end to end, from the nine principles to the Core KPIs, that is exactly what we teach step by step in our BRSR Reporting Bootcamp at Sustainability 101.

Keep reading: GHG Protocol vs ISO 14064, which one does your company actually need? and our plain-English guide to GHG emission disclosure in India.

SEBI's direction is clear, even where the deadlines are gentle. The numbers are going to be checked. The only choice is whether you prepare for it early, at your own pace, or later, at someone else's deadline.