Collaboration Between ISO and the GHG Protocol: A Strategic Partnership as a Milestone in Carbon Accounting

On September 9, 2025, both ISO and the GHG Protocol announced their new strategic partnership. The goal of this partnership is to develop common and harmonized standards for greenhouse gas reporting in the future.

This “ISO GHG Protocol Partnership” marks an effort to bring together systems that have previously operated in parallel and, in some cases, competed with one another. For companies worldwide, this means a potential simplification of their reporting and verification processes—and, at the same time, a new direction in a field that has previously been characterized by fragmentation.

Background: An Overview of the ISO 14064 Family and the GHG Protocol

For years, these two frameworks have been regarded as the leading standards in carbon accounting —and yet, to this day, they speak different languages.

• ISO 14064 and its three main parts:
  • ISO 14064-1: Specification and guidelines for the quantification of greenhouse gas emissions at the organizational level.
  • ISO 14064-2: Methodology for project emissions (e.g., mitigation projects, offsetting).
  • ISO 14064-3: Requirements for verification and validation —and thus the primary reference for external audit processes.
    

• GHG Protocol: The Greenhouse Gas Protocol was developed in the early 2000s by WRI and WBCSD and is now the most widely used corporate standard worldwide. Its components:
  • Corporate Standard (Scopes 1–3)
  • Scope 2 Guidance and Scope 3 Standard
  • Product Life Cycle Accounting and Project Protocol
    

While ISO is firmly rooted in the field of auditability, the GHG Protocol has gained widespread market adoption and serves as the basis for many regulations and ESG software solutions.

The partnership will establish a common global framework for emissions accounting, which will accelerate progress toward decarbonization (...) and cover standards for corporate, product, and project accounting and verification.

The New Alignment: What Does the Partnership Mean?

Today’s announcement is more than just a symbol of cooperation: it aims to harmonize GHG standards in practice. Until now, two sets of standards have developed in parallel: the ISO 1406x family on one hand, and the GHG Protocol standards on the other. Companies have sometimes had to apply these standards in parallel, leading to duplication of effort, uncertainty, and limited comparability.

This new partnership aims to address this issue. ISO and the GHG Protocol aim to:

• harmonize existing standards,
• develop new, co-branded standards,
• Reduce complexity in reporting and
• increase comparability and acceptance worldwide.

Planned measures

• Introduction of co-branded standards that combine ISO methodology and GHG Protocol logic.
• Top priority: a common product life cycle assessment standard to unify the currently highly fragmented landscape (ISO 14067, GHG Product Standard).
• Common terminology catalog for reporting, scopes, and verification.

Objective

• Eliminating duplicate structures: In the future, companies should no longer have to maintain two parallel systems.
• Global consistency: a standardized "vocabulary" for carbon accounting.
• Relief for companies seeking to streamline their reporting processes and improve verifiability.
  
  

Important for businesses: Until the new standards are finalized, the existing ISO and GHG Protocol standards remain in effect. So no one needs to switch over overnight—but it’s worth preparing for the new harmonization early on.

Which standards are affected?

The partnership covers corporate, product, and project accounting as well as verification. This includes, among other things:

• ISO 1406x series (Corporate, PCF, Project Accounting, Verification)
• GHG Protocol Corporate Standard, including Scope 2 Guidance and Scope 3 Standard
• Development of a Common Product Carbon Footprint (PCF) Standard
  

This means that, for the first time, harmonization will affect not only corporate balance sheets but also product-specific carbon footprints —an area of growing importance for supply chain management, CBAM implementation, and decarbonization strategies in Europe.

Comparison: ISO 14064 vs. GHG Protocol – Current Content and Differences

Although both standards have similar objectives, they differ in scope, application logic, and the level of verification.

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ISO’s strengths clearly lie in verification and auditability, while the GHG Protocol has established itself as the market’s “lingua franca” and is deeply embedded in regulatory frameworks (e.g., CSRD, SEC, ISSB).

Relevance for Businesses: What Does Alignment Mean in Practice?

For companies that already align their climate strategy and reporting with one of these standards, the partnership is highly relevant:

• Advantages
  • Simplification of processes, less duplication of effort.
  • Standardized definitions and more consistent data structures.
  • Greater efficiency in reporting and verification.
• Risks & Challenges
  • A transitional phase with potentially conflicting demands.
  • Variations in the pace of adoption by regulators.
  • Coordination with auditors and certifiers is necessary.

Our recommendation: Companies should review their current reporting architecture and assess the synergies that harmonization will bring in the medium term.

Opportunities & Benefits for Businesses

The partnership offers several benefits:

• Consistency: Consistent rules reduce room for interpretation and enhance credibility in the markets and among investors.
• Efficiency: Reduced duplication of effort in reporting, particularly for companies operating globally.
• Supply Chain Capability: A new PCF standard facilitates the collection and sharing of emissions data across complex value chains.
• Regulatory interoperability: Harmonization facilitates compatibility with CSRD/ESRS, CBAM, and international regulations.
• Verification & Assurance: Consistent guidelines strengthen the foundation for audits and reduce costs.

Challenges and Limitations

• Transition phase: Until new standards are finalized, existing rules will coexist. Companies must carefully prioritize which standard to follow today to avoid having to make duplicate adjustments tomorrow.
• Scope 3 data: Even harmonized standards do not solve the fundamental challenge of poor data quality in supply chains. Companies should proactively invest in this area.
• Removals & Land Sector: Since these areas are not included in the co-development, there remains uncertainty as to how and when integration will take place.

The View

As of September 25, 2025

The ISO–GHG Protocol partnership is more than just a formal alignment. It could bring about lasting change to the reporting ecosystem and lay the groundwork for global comparability in carbon accounting.

Next step:‍

Companies should now assess how they can prepare their corporate carbon footprints (CCF), Scope 3 accounting, and product carbon footprints (PCF) for the upcoming harmonization—while leveraging the synergies with ESRS E1 and climate transition plans.

What happens next?

The joint working groups have begun development. An official timeline for completion has not yet been announced, but the first release is expected in 2026. Until then, early preparation provides clarity and a competitive edge.

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Source & further information

ISO–GHG Protocol Partnership FAQ (2025)‍

Do you need assistance with implementation or verification?

Contact us—we’ll provide strategic and operational support to help you achieve a harmonized, sustainable climate management system.

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