BRSR Core Assurance is Now Mandatory for All Top 1000 Companies

SEBI’s BRSR Core assurance requirement is fully in force. Here is what changes, what auditors expect, and how to stay ahead.

For most of its early years, ESG reporting in India was a disclosure exercise. Companies gathered what they had, filled in the format, and filed. The data told a story, but no one was checking whether the story was accurate.

With the onset of FY 2026-27, that era is now closing. BRSR Core assurance has become mandatory for all top 1000 listed companies, completing a phased rollout that began with India’s top 150 companies in FY 2023-24.

BRSR Core Assurance Rollout Timeline

Financial Year	Coverage
FY 2023-24	Top 150 companies
FY 2024-25	Top 250 companies
FY 2025-26	Top 500 companies
FY 2026-27	All top 1000 companies

Every ESG metric under BRSR Core now requires independent third-party verification, applying the same rigor expected of financial statements.

By FY 2026-27, reasonable assurance on BRSR Core is mandatory for all top 1000 listed companies by market capitalization, placing India among the world’s most rigorous ESG assurance regimes.

What Comes Under “Reasonable Assurance”

Reasonable assurance requires auditors to:

• Trace disclosed metrics back to source documents.
• Verify calculation methods are consistent and documented.
• Assess whether internal controls produce reliable data year after year.

BRSR Core covers nine specific ESG attributes:

• Greenhouse Gas Emissions
• Water Management
• Gender Diversity
• Energy Consumption
• Waste Management
• Customer Conduct
• Inclusive Development
• Wages Distribution
• Business Openness

For each attribute, auditors will verify not only the numbers but also the systems behind them.

Core Areas Auditors Evaluate

• Data Origin
• Data Ownership
• Calculation Methodology
• Error Prevention

The quality of ESG data is now determined by how effectively that data is governed. A company may have strong sustainability performance but still receive assurance findings if its data infrastructure is fragmented or inconsistently managed.

The value chain adds another layer. From FY 2026-27, ESG disclosures for upstream and downstream partners individually contributing 2% or more of purchases or sales are subject to assessment or assurance. The data boundary now extends beyond company walls.

Verified ESG Data Is Becoming a Business Asset

India’s move to mandatory ESG assurance reflects a broader global trend. Investors are applying more structured ESG criteria to capital allocation. Supply chains increasingly require verified sustainability data from partners, while credit agencies are incorporating environmental and governance performance into their assessments.

Verified ESG data carries credibility that disclosed but unverified data cannot. Companies building rigorous ESG data infrastructure are creating an asset that strengthens investor confidence, regulatory readiness, procurement relationships, and long-term market positioning.

Organizations treating assurance as a one-time compliance exercise may find themselves rebuilding processes every year. Those treating it as an infrastructure investment will benefit from easier audits, richer data, and more useful reporting.

What the Infrastructure Looks Like

Most companies already have pieces of this infrastructure. The challenge is connecting those pieces. ESG data typically resides across operations, HR, procurement, and facilities.

When data flows through a unified platform rather than spreadsheets and email threads:

• Traceability becomes automatic.
• Consistency becomes structural.
• Governance becomes visible.

How Benchmark Gensuite Helps

Benchmark Gensuite’s Sustainability and Disclosure Management Suite is designed around SEBI’s framework and its assurance requirements.

The platform:

• Centralizes ESG data collection across functions and locations.
• Connects with ERP and HRIS systems.
• Automates calculations using standardized methodologies.
• Maintains consistent conversion factors and formulas across sites.
• Provides complete audit trails with timestamped records and source documentation.

The platform comes preconfigured for all nine BRSR Core attributes, including validation rules and approval workflows that identify gaps before reporting deadlines.

Real-time dashboards provide sustainability leaders with year-round visibility across the organization, allowing teams to focus on performance trends, improvement opportunities, and strategic decision-making rather than manual data compilation.

This Is the Perfect Preparation Window

FY 2026-27 assurance will be based on data collected this year. Organizations that have already operated under assurance requirements show a consistent pattern: each year, the process becomes more efficient, the data becomes more complete, and reporting becomes more strategically valuable.

For companies entering the assurance framework in FY 2026-27, now is the opportunity to build the necessary infrastructure and benefit from lessons learned by earlier cohorts.

A purpose-built ESG platform can help transform verified, investor-grade ESG data from a compliance obligation into a permanent operational capability.