BRSR Core in FY 2026-27: assurance reaches the top 1,000 listed companies

India's Business Responsibility and Sustainability Report has been mandatory for the top 1,000 listed companies since FY 2022-23. What changes in FY 2026-27 is not whether they report, but whether the core numbers are independently checked. That step is where most of the effort, and most of the risk, now sits.

The glide path

The top 1,000 is measured by market capitalisation. Moving from 500 to 1,000 brings in hundreds of mid-cap companies, many with a lean sustainability function and no history of external review of their greenhouse-gas, energy, water and waste numbers.

Assessment or assurance

SEBI's circular of 28 March 2025 (SEBI/HO/CFD/CFD-PoD-1/P/CIR/2025/42) changed "assurance" to "assessment or assurance". Companies can now choose an assessment carried out under standards set by the Industry Standards Forum instead of a full assurance engagement. Either way, a third party has to be able to trace the reported Core indicators back to evidence.

The value chain, recalibrated

The same circular softened the value-chain requirement. ESG disclosure for the value chain is voluntary from FY 2025-26, and its assessment or assurance is voluntary from FY 2026-27. It applies to the top 250 listed entities. The value chain is now limited to upstream and downstream partners that each account for 2% or more of the company's purchases or sales by value. The circular also introduced voluntary green-credit disclosure in the BRSR.

What newly in-scope companies should prepare

• An inventory of Core indicators with source evidence for each figure: bills, meter logs, fuel records and HR data.
• A documented method for each calculation, including which emission factors were used and why.
• Internal controls a third party can test: who entered the data, who reviewed it, and what changed.
• A choice of assessment or assurance provider made early. Capacity is limited in the first year of a new cohort.

ZeroCarbon produces BRSR outputs from the same ledger that holds each figure's source document, factor and approval history. That is the trail an assessor or assurance provider will ask to see.