ESG Assurance Services
RSustain is an AA1000-licensed assurance provider, authorised to conduct independent sustainability assessments across 11 SASB sectors. Service coverage spans 5 jurisdictions (4 incorporated entities plus UAE operations). We combine regulatory expertise (SEBI BRSR) with global assurance standards (AA1000AS v3, ISAE 3000) and technology-enabled delivery.
Independence Is Non-Negotiable
Credible assurance requires independence at the provider, associate, and client-group level — not just team separation. RSustain applies the following safeguards, which are assessed on an engagement-specific basis before any assurance work begins.
Note: Internal safeguards such as team separation and information barriers supplement, but do not replace, the provider-level and regulatory independence requirements applicable to each engagement.
Choose Your Assurance Path
From first-time readiness checks to full independent assurance — we meet you where you are.
Pre-Assurance Validator
Not sure if your ESG data is audit-ready? Run our diagnostic first. Validates your BRSR data against 5–9 core KPIs, sector benchmarks, and assurance standards.
- Free tier: 5 KPIs validated
- Professional: Full 9 KPI assessment (₹14,999)
- Sector benchmark comparison
- Assurance readiness score (0–100)
- Red / Amber / Green flags with remediation
- Instant results
Takes 10 minutes. No commitment required.
BRSR Core Assurance Sprint
12-week advisory programme to prepare your BRSR Core data, controls, and evidence for independent third-party scrutiny. For SEBI-mandated companies ranked in the top 1,000.
- All 9 BRSR Core ESG attributes (49 KPIs)
- ISAE 3000 (Revised) methodology
- Limited or Reasonable assessment
- Mock audit + evidence preparation
- Data architecture review
- Board-ready report
- Management letter with recommendations
For companies ranked 150–1,000 by market cap.
AA1000 Remote Assurance
Full AA1000AS v3 assurance engagement conducted entirely online. Type 1 (principles) or Type 2 (principles + data), with High or Moderate assurance levels.
- 4 AccountAbility Principles assessed
- 32 evaluation criteria
- Type 1 or Type 2 engagement
- High or Moderate assurance level
- Remote evidence collection + interviews
- Formal assurance statement
- Remote delivery reduces overhead vs. traditional providers
Online pricing calculator available.
What We Assess — 9 BRSR Core Attributes
SEBI mandates assessment of these 9 ESG attributes under BRSR Core. Our assurance covers all 49 underlying KPIs.
Six-Step Assessment Process
A rigorous, transparent methodology from scoping to final report — designed for efficiency without compromising assurance quality.
Scoping & Independence Check
Week 1
Conflict register review, scope definition, fee proposal, engagement letter. Independence is verified before any work begins.
Planning & Risk Assessment
Week 2
Assessment plan, evidence requirements, materiality thresholds, team assignment. Every engagement gets a tailored plan.
Evidence Collection & Review
Weeks 3–6
Document review, data verification, calculation reperformance, evidence quality audit. We examine source data, not just reported figures.
Testing & Interviews
Weeks 5–8
Management interviews, site-level checks (virtual for remote engagements), analytical procedures, stakeholder engagement review.
Draft Findings & Management Response
Weeks 9–10
Preliminary findings shared, management responses documented, factual accuracy confirmed. No surprises in the final report.
Final Report & Statement
Weeks 11–12
Formal assessment report, assurance statement, management letter, board presentation, debrief call. Delivered in formats ready for regulatory filing.
Licensed Across 11 SASB Sectors
RSustain holds AA1000 assurance licences covering 11 SASB industry sectors, enabling us to conduct independent assessments across virtually every segment of the Indian economy.
RSustain is verified in AccountAbility's global directory of licensed assurance providers.
Why RSustain
Ready for Independent Assurance?
Start with our free Pre-Assurance Validator, explore the BRSR Core Sprint, or get an instant AA1000 quote.
Assurance Services FAQ
What is the difference between AA1000 and ISAE 3000 assurance?
AA1000AS v3 is principles-based, evaluating Inclusivity, Materiality, Responsiveness, and Impact (Type 1 = principles only, Type 2 = principles + data). ISAE 3000 (Revised) is procedures-based, providing limited or reasonable assurance on non-financial data. Many engagements combine both. SEBI's BRSR Core assurance typically references ISAE 3000.
Does RSustain have an AA1000 licence for India?
Yes. RSustain holds an AA1000 licence from AccountAbility covering 11 SASB sectors across 5 jurisdictions including India. The licence authorises independent sustainability assessments under AA1000AS v3.
Which standard should I choose?
For BRSR Core assurance: ISAE 3000. For GHG: ISAE 3410. For broader sustainability (stakeholder engagement, materiality, management approach): AA1000AS v3. For comprehensive coverage: combined AA1000 + ISAE 3000.
How long does an assurance engagement take?
Limited assurance: 4-8 weeks. Reasonable assurance: 8-12 weeks. Timeline depends on scope (KPIs and sites), data readiness, and complexity. Start preparation 3-6 months before the engagement.
Can the same firm provide advisory and assurance?
Independence is fundamental. If RSustain provides advisory (e.g., BRSR report preparation), a separate independent practitioner must conduct assurance. We manage this through engagement-specific independence reviews.