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Measure & Report  ·  1.3.1

Third-Party Verification

Third-party verification provides independent confirmation that a company's GHG inventory and sustainability disclosures are accurate, complete, and consistent with stated methodology. It is the primary mechanism for making sustainability claims credible to investors, regulators, and customers. The assurance landscape is evolving rapidly — limited assurance is increasingly table stakes, while reasonable assurance is becoming the standard for regulatory compliance.

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Self-Assessment

Select where your organization currently operates and where you want to get to. There is no obligation to reach "Leading Org." — choose the target that is right for your business context and investment capacity.

📍 Current Level
🎯 Target Level
Select your current and target levels above to map your assessment on this initiative.
Fundamental
Market Standard
Above Average
Leading Org.

Technology

  • Self-declaration of GHG inventory with internal methodology documentation but no external verification
  • ISO 14064-1 standard reviewed as framework for inventory preparation in preparation for future verification

Process

  • Documenting inventory methodology, data sources, and calculation assumptions in a written inventory management plan
  • Conducting an internal review of emissions data for completeness and reasonableness before publication
  • Identifying a qualified verifier (accredited under ISO 14065 or equivalent) for future engagement

Financing

  • No external verification cost at this stage
  • Internal documentation investment treated as foundational preparation for assurance readiness

Technology

  • Fundamental Technologies +
  • Limited assurance engagement on Scope 1 and 2 GHG inventory from accredited verifier (ISO 14065)
  • Verification statement published alongside GHG inventory in sustainability report or CDP response

Process

  • Engaging an accredited third-party verifier to conduct limited assurance on Scope 1 and 2 emissions
  • Preparing for verification: organizing evidence, data trails, and methodology documentation for verifier review
  • Addressing material findings from verification process and updating inventory controls accordingly

Financing

  • Limited assurance engagement cost: $20K–100K depending on organizational complexity and scope
  • Verification cost justified by CDP scoring uplift, investor expectations, and regulatory preparedness

Technology

  • Market Standard Technologies +
  • Limited assurance extended to cover material Scope 3 categories in addition to Scope 1 and 2
  • Verification conducted annually with same verifier to build institutional knowledge and audit efficiency

Process

  • Expanding verification scope to include Scope 3 Categories 1, 11, and other material categories
  • Implementing internal controls over sustainability reporting (ICSR) to streamline annual verification process
  • Using verifier management letter findings to drive continuous improvement in data quality and controls

Financing

  • Extended Scope 3 verification cost: $50K–300K depending on category coverage and data complexity
  • ICSR implementation reduces verification time and cost over multi-year engagement

Technology

  • Above Average Technologies +
  • Reasonable assurance on full GHG inventory (Scope 1, 2, and 3) and sustainability statement from Big 4 or equivalent
  • Continuous monitoring controls enabling real-time data quality flagging between annual verification cycles

Process

  • Achieving reasonable assurance — the highest standard of independent verification — across all material disclosures
  • Verification scope aligned with CSRD/ISAE 3000 requirements, satisfying both voluntary and regulatory standards
  • Publishing full verifier's report including methodology, scope limitations, and findings in annual sustainability report

Financing

  • Reasonable assurance engagement cost: $200K–1M+ for large organizations with complex Scope 3
  • Assurance cost offset by regulatory compliance value, reduced ESG rating scrutiny, and investor confidence premium

Related Pathways

← All Pathways 5.3.2 Internal Audit & Controls 5.3.3 Registry & Attribution 5.2.1 Voluntary Frameworks