BRSR assurance vs assessment: what SEBI's March 2025 circular changed

SEBI's March 28, 2025 circular introduced a significant change to the BRSR Core verification framework: "assessment" now exists alongside full "reasonable assurance" as a pathway for independently verifying the 42 BRSR Core KPIs. For consultants advising top-500 companies, understanding the difference between these two pathways, and which companies can opt for which, is essential before your client appoints a verifier.

Before March 2025: one pathway, one bar

Before SEBI's March 2025 circular, the only permitted pathway for BRSR Core verification was reasonable assurance under ISAE 3000. ISAE 3000 (Assurance Engagements Other than Audits or Reviews of Historical Financial Information) is the international standard for non-financial assurance. Reasonable assurance under ISAE 3000 requires the assurer to obtain sufficient evidence to express a positive opinion, equivalent to a statutory financial audit in terms of the evidence burden. This is a high bar, and it was the only option available.

What the March 2025 circular changed

SEBI's circular dated March 28, 2025 introduced "assessment" as an alternative pathway. Assessment is an evaluation of whether the reported BRSR Core KPIs comply with the sector-specific standards published by the Industry Standards Forum (ISF) in December 2024. It is less onerous than ISAE 3000 reasonable assurance but still requires an independent evaluator and a structured evidence review. Assessment is not a self-certification; it requires an independent third party.

What assessment involves in practice

Under the assessment pathway, the independent evaluator reviews whether the company has measured each of the 42 Core KPIs in accordance with the relevant ISF sector standard. This includes reviewing the measurement methodology, the calculation approach, and whether the reported boundary (which sites and activities are included) matches the ISF standard requirements. The evaluator issues an assessment report, which is included in the Annual Report alongside the BRSR.

What full reasonable assurance involves in practice

Full reasonable assurance under ISAE 3000 goes further. The assurer tests the data at source level through site visits, reviews primary documents (utility bills, HR system exports, sub-meter readings), traces data from site level to company-level aggregation, evaluates internal controls over ESG data, and issues a positive opinion. The scope of work is materially larger than an assessment engagement.

The ISF sector standards: what they are

The Industry Standards Forum published sector-specific BRSR Core Standards in December 2024. These are binding guidance documents that specify how each of the 42 Core KPIs should be measured for each sector covered. They address sector-specific issues such as whether GHG intensity should be per tonne of product or per unit of energy for a given sector, and how water intensity denominators should be defined for water-intensive industries. The ISF standards are published on the SEBI website. Reviewing them before data collection begins will save significant rework later.

Timeline for preparation

Regardless of which pathway your client chooses, start preparation for BRSR Core verification at least four to six months before the Annual Report filing deadline. For FY 2025-26, with Annual Reports typically due by September or October 2026, that means starting by April 2026 at the latest. Companies that approach the assurer or assessment agency in August with incomplete data and undocumented methodologies will either miss the deadline or receive a qualified opinion.

• By April 2026: data collection launched, named data owners assigned per KPI, ISF sector standard reviewed.
• By June 2026: primary source data collected, calculation methodology documented, assurer or assessor appointed.
• By July 2026: assurer begins field work or evidence review.
• By August 2026: assurance statement or assessment report drafted and reviewed.
• By September 2026: opinion finalised, included in draft Annual Report.

Key takeaways

• SEBI March 2025 introduced assessment as an alternative to full ISAE 3000 reasonable assurance for BRSR Core KPIs.
• Assessment is based on ISF sector-specific standards published in December 2024. It requires an independent evaluator but is less onerous than full assurance.
• The criteria for who can choose assessment vs must do full assurance are in the SEBI March 28, 2025 circular. Read it before advising a client on pathway choice.
• Start verification preparation four to six months before the Annual Report deadline regardless of pathway.
• The ISF standards are the reference document for measurement methodology under either pathway.