BRSR, BRSR Core, BRSR Lite — The Sustainability Reporting Stack Explained

If your client is listed and you still think of Business Responsibility and Sustainability Reporting as a single annual chore, the 2026 update will catch you out. BRSR has quietly become a three-layered regime — Full BRSR, BRSR Core, BRSR Lite — each with different applicability, different assurance requirements, and a meaningfully different scoping cost. This article unpacks what each one is, who has to file what in FY26, and how to scope the work without setting up a separate ESG team.

The three layers

Full BRSR — the top 1,000 listed entities

Mandatory for the top 1,000 listed entities by market cap. Published as part of the annual report. Nine principles, hundreds of disclosures, both essential and leadership indicators. The full document.

BRSR Core — the top 250 listed entities

A focused subset of BRSR, specifically the KPIs SEBI considers material enough to require reasonable assurance from a third party. From FY24 it applied to the top 150; from FY25, top 250; from FY27, value chain partners (top suppliers + customers) for the top 250 also come into scope.

BRSR Lite — the next 1,000 listed entities

A simplified format for the listed entities ranked 1,001 to 2,000 by market cap. Voluntary in FY25, mandatory from FY26. Fewer KPIs, simpler disclosures, no third-party assurance — but still board-approved.

What changed in 2026

• Value chain reporting is now mandatory for the top 250 from FY27. Identify your top upstream and downstream value chain partners (95% of purchases / sales by value) and disclose their environmental and social KPIs.
• BRSR Core assurance providers must now be registered with SEBI. The earlier ambiguity around who counts as a credible assurance provider is gone.
• Industry-specific KPIs have been published for nine sectors (cement, steel, oil & gas, chemicals, IT, banking, FMCG, pharma, auto). Apply on top of the base disclosures.
• Quarterly BRSR Core indicators are being piloted for the top 50 listed entities. Expect this to be mainstreamed in FY28.

The realistic effort

The chart above is the most honest map we can offer. Over half the effort is just collecting data from operations — energy consumption by facility, water withdrawal, gender split by function, training hours by category, suppliers verified for child labour and forced labour. None of this is hard. All of it requires somebody owning the spreadsheet.

The CS team rarely owns the underlying data. The CS team owns the disclosure framework, the board approval workflow, and the timing. The mistake we see most often is the CS team trying to own everything, then becoming the bottleneck.

A workable scoping playbook

1. Anchor on the report calendar. Board approval of the annual report is the deadline. BRSR sign-off is two weeks before that. Work backwards.
2. Identify the data owners. One named owner per BRSR Core indicator. The CS team's job is to chase, validate, consolidate — not produce.
3. Pre-engage the assurance provider. Reasonable assurance takes time. Bring them in at the Q2 board, not the Q4.
4. Lock the prior-year baseline. Almost every disclosure is comparative. The number you publish this year becomes the comparator next year — make sure it is the right number now.
5. Pilot value chain disclosure in FY26 even if not mandatory. The top 250 know FY27 is coming. Practising the data ask with three or four value chain partners this year will save chaos next year.

How Delta Filings helps

BRSR is one of the longest filings a listed entity makes in a year, and the one where errors are most public. Delta Filings ingests every BRSR filing on the exchanges as it happens, indexes the KPIs, and lets you benchmark a client's draft against peer companies in the same sector before it is filed. The number of times we have caught a clearly out-of-range disclosure before it embarrassed a CFO is non-trivial.

The strategic note

BRSR is going to look like CSR in five years' time — a regime that everyone resisted, then accepted, and which eventually rewrote how Indian boards think about non-financial performance. The CS teams that build the data pipes early will be the ones running this for the C-suite by FY28.