SEBI's phased introduction of BRSR assurance requirements has moved sustainability reporting from a disclosure exercise into a rigorous accountability framework. For the top 150 listed companies by market capitalisation, reasonable assurance on BRSR Core indicators is now mandatory — and the scope is expanding to the broader top 1,000 cohort.
Understanding BRSR Core vs. Full BRSR
SEBI has structured BRSR into two tiers. The full BRSR encompasses 98 data points across nine principles of the National Guidelines on Responsible Business Conduct (NGRBC). The BRSR Core is a subset of key performance indicators subject to mandatory third-party assurance.
BRSR Core KPIs span environmental metrics (GHG emissions Scope 1 and 2, energy intensity, water intensity), social metrics (employee turnover, wages, occupational health) and governance metrics (anti-corruption training, political contributions). These are precisely the indicators that institutional investors use in portfolio screening models.
"Companies that treat BRSR assurance as merely a compliance obligation miss the point. Assurance-ready data infrastructure is the foundation for sustainability-linked finance and investor-grade disclosure."
Common Gaps We Encounter
In our work with listed entities preparing for BRSR assurance, we consistently identify three categories of gaps. The first is data infrastructure — most companies lack systems to collect, consolidate and verify sustainability data at the frequency and granularity that assurance requires. Energy and emissions data often exists in operational silos; aggregating it into a reliable, audit-trail-backed dataset requires deliberate system design.
The second gap is boundary definition. Companies are often uncertain about which entities, geographies and operations should be included in their BRSR reporting boundary — particularly in complex group structures with subsidiaries, associates and joint ventures.
The third — and most commonly underestimated — gap is assurance process readiness. Many companies have never undergone a sustainability assurance engagement and are unprepared for the level of documentation, evidence and management representation that assurance providers require.
A Practical Preparation Roadmap
Effective BRSR assurance preparation typically unfolds over three to six months. The first phase is a readiness assessment — mapping current data availability against BRSR Core requirements and identifying material gaps. The second phase is system and process design — establishing data collection workflows, appointing internal owners for each KPI, and implementing controls that can be evidenced to an assurance provider. The third phase is a pre-assurance review — an independent assessment of the data, processes and disclosures before formal assurance commences.
Key Takeaways
- BRSR Core assurance is mandatory for top 150 listed companies; expanding to top 1,000
- BRSR Core covers GHG emissions (Scope 1 & 2), energy/water intensity, employment metrics and governance KPIs
- Three most common gaps: data infrastructure, reporting boundary definition, assurance-process readiness
- Preparation typically requires 3–6 months — begin well before the reporting cycle
- Assurance-ready BRSR disclosure unlocks sustainability-linked financing at better terms