What is ISO 14064? A Complete Guide to the Greenhouse Gas Accounting Standard

Sustainability and climate reporting have moved from voluntary to mandatory across much of the European business landscape. Frameworks like the Corporate Sustainability Reporting Directive (CSRD) and the EU Taxonomy now require standardized, auditable greenhouse gas disclosures that stand up to investor scrutiny, regulatory assurance, and public accountability.

While many companies previously relied on flexible, principle-based frameworks such as the GHG Protocol, ISO 14064 has become the gold standard for audit-ready carbon footprint reporting. It allows businesses to quantify emissions in line with international best practices and provides the technical rigour necessary for third-party verification, an essential step under CSRD Article 26.

The growing regulatory focus on Scope 3 emissions, external assurance, and science-based targets means companies must move beyond spreadsheets and inconsistent methodologies. ISO 14064 helps bridge the gap between climate ambition and verifiable action by establishing a structured, harmonized approach to GHG management.

In short: if you’re looking to future-proof your climate disclosures, comply with CSRD, or establish credibility in the market, ISO 14064 isn’t optional - it’s strategic.

The ISO 14064 standard is organized into three interrelated parts that cover everything from calculating emissions to verifying results. Each part targets a different level of emissions management -organizational, project-based, and verification. Understanding how these components work together is critical for building a transparent and compliant carbon strategy.

ISO 14064-1: Quantifying Emissions at the Organizational Level

ISO 14064-1 is the foundation of the standard and applies to entire organizations. It outlines principles and detailed requirements for quantifying and reporting GHG emissions and removals across all business activities.

This part is essential for producing a Corporate Carbon Footprint (CCF), a mandatory disclosure under ESRS E1. It guides organizations in:

• Setting organizational and operational boundaries
• Identifying direct and indirect emission sources (Scope 1, 2, and 3)
• Selecting appropriate data sources and emission factors
• Applying consistent quantification methodologies
• Ensuring data quality and transparency through documentation and management systems

ISO 14064-1 is particularly valuable for organizations looking to embed GHG accounting into their core business practices. It ensures consistency across reporting cycles, supports decarbonization planning, and lays the groundwork for external verification.

ISO 14064-2: Project-Based Emissions Reductions

While ISO 14064-1 focuses on an organization's total emissions, ISO 14064-2 is designed for specific projects that aim to reduce or remove greenhouse gases.

Use cases include:

• Energy efficiency retrofits
• Renewable energy installations
• Carbon capture or storage projects
• Land use or reforestation programs

It provides guidance on defining baselines, estimating emissions reductions, tracking results, and monitoring performance over time.

ISO 14064-2 is especially relevant for organizations implementing decarbonization initiatives or participating in voluntary or compliance-based carbon markets. It ensures that emissions reductions are measurable, reportable, and verifiable - core criteria for high-integrity climate action.

ISO 14064-3: Verification and Assurance of GHG Disclosures

The third part of the standard, ISO 14064-3, outlines the requirements for validating and verifying GHG assertions made under Parts 1 and 2.

It defines:

• How external verification bodies should assess GHG inventories
• Required documentation and evidence
• The level of assurance (limited or reasonable)
• The scope, objectives, and criteria of the verification process

This section is critical for CSRD compliance, which mandates third-party assurance of GHG data beginning in 2026. ISO 14064-3 provides the framework for these verifications to be carried out consistently and credibly.

Organizations that proactively structure their reporting to meet ISO 14064-3 requirements are better prepared for audits, investor scrutiny, and regulatory filings.

While both ISO 14064 and the GHG Protocol are widely accepted for carbon accounting, they differ in structure, purpose, and application. Knowing when to use each- or both together - can help your organization build a carbon strategy that is both flexible and audit-ready.

Key Differences Between ISO 14064 and GHG Protocol

1. Framework Type

• ISO 14064: A technical, certifiable standard developed by the International Organization for Standardization.
• GHG Protocol: A voluntary framework developed by NGOs (WRI and WBCSD) for guiding carbon accounting globally.

2. Level of Detail

• ISO 14064 provides specific technical requirements, making it suitable for audit and assurance.
• GHG Protocol is more principle-based, offering flexible guidance and best practices.

3. Verification and Assurance

• ISO 14064 includes a full methodology for third-party verification (Part 3).
• GHG Protocol does not prescribe verification processes.

4. Regulatory Alignment

• ISO 14064 is better suited for compliance with CSRD, EU Taxonomy, and science-based target validation.
• GHG Protocol is often used for voluntary reporting, CDP disclosures, and value chain mapping.

5. Scope 3 Emissions

• GHG Protocol is more detailed in its treatment of Scope 3 emissions (15 categories).
• ISO 14064-1 covers Scope 3 but with fewer specific guidelines, which makes combining the two frameworks ideal for full value chain analysis.

6. Use Cases

• Choose ISO 14064 when preparing for audits, aligning with CSRD, or seeking third-party assurance.
• Use GHG Protocol when starting your carbon journey or focusing on complex Scope 3 mapping.

Recommendation: Most companies in the EU choose to combine both - using GHG Protocol to identify and categorize emissions, and ISO 14064 to structure, report, and verify them in a compliant, auditable way.

The Corporate Sustainability Reporting Directive (CSRD) significantly raises the bar for environmental disclosures. Under ESRS E1, companies must report on their GHG emissions across Scopes 1, 2, and 3, using standardized, audit-ready metrics.

ISO 14064 helps companies align with CSRD in several ways:

• ISO 14064-1 supports the structure and documentation required for ESRS-aligned reporting.
• ISO 14064-3 meets the assurance requirements for limited assurance (2026) and reasonable assurance (2028+).
• ISO’s rigorous quantification principles mirror those outlined in ESRS, including transparency, consistency, completeness, and accuracy.
• The standard enables traceability and accountability across quantification methods, data sources, and organizational boundaries critical for assurance and audit-readiness.

Companies that adopt ISO 14064 early are better positioned to integrate ESG data into financial disclosures, respond to stakeholder requests, and meet EU legal obligations without scrambling at the last minute.

Technically, ISO 14064 is not mandatory but in practice, its adoption is rapidly becoming the norm for companies subject to regulatory and investor scrutiny.

• CSRD requires third-party assurance, and ISO 14064-3 provides the framework
• Customers and suppliers increasingly request ISO-aligned data as part of ESG procurement requirements
• Financial institutions use ISO-compliant disclosures to assess climate-related risk
• ISO 14064 certification serves as a trust signal in sustainability ratings and due diligence

While not legally enforced yet, ISO 14064 is becoming a de facto requirement for companies seeking to stay competitive, manage reputational risk, and future-proof their climate strategy.

What is ISO 14064?

ISO 14064 is an international standard developed by the International Organization for Standardization (ISO) that defines how organizations and projects should quantify, report, and verify greenhouse gas (GHG) emissions.

The standard provides a structured and technically robust framework to ensure that carbon footprints are accurate, transparent, consistent, and auditable. It is widely used by companies across industries to support regulatory reporting, investor disclosures, and climate strategies.

ISO 14064 is particularly relevant in the European context, as it aligns closely with the requirements of the Corporate Sustainability Reporting Directive (CSRD) and the European Sustainability Reporting Standards (ESRS), especially for Scope 1, 2, and 3 emissions reporting and external assurance.

What is the difference between ISO 14064-1 and ISO 14064-3?

The two parts serve different but complementary purposes:

• ISO 14064-1 focuses on how to build a greenhouse gas inventory. It defines requirements for identifying emission sources, setting organizational boundaries, selecting quantification methods, managing data quality, and reporting emissions at the organizational level. It is the basis for creating a Corporate Carbon Footprint (CCF).
• ISO 14064-3 defines how that inventory is independently verified. It sets the rules for third-party validation and verification, including audit scope, evidence requirements, assurance levels, and verification statements.

In practice, ISO 14064-1 is about doing the carbon accounting, while ISO 14064-3 is about proving that the accounting is correct. Together, they enable audit-ready, credible climate disclosures.

Is ISO 14064 required for CSRD compliance?

ISO 14064 is not explicitly mandated by CSRD, but it is one of the most widely accepted and practical ways to meet CSRD requirements in practice.

Under CSRD, companies must:

• Report Scope 1, 2, and 3 emissions under ESRS E1
• Ensure data is consistent, traceable, and well-documented
• Undergo third-party limited assurance, with reasonable assurance expected in later phases

ISO 14064-1 supports the structure and rigor required for ESRS-aligned GHG reporting, while ISO 14064-3 provides a recognized framework for external assurance. For this reason, many auditors, regulators, and verification bodies expect or strongly prefer ISO 14064-aligned methodologies.

In short: ISO 14064 is not legally required, but it is highly CSRD-compatible and often the safest choice.

Can I use ISO 14064 and the GHG Protocol together?

Yes, many organizations do. ISO 14064 and the GHG Protocol are often used in a complementary way.

A common approach is:

• Use the GHG Protocol to structure emissions by Scope 1, 2, and 3 and to apply detailed guidance, especially for complex Scope 3 categories.
• Use ISO 14064 to formalize the quantification, documentation, and verification process in a way that is audit-ready and compliant with regulatory expectations.

This combined approach offers the best of both worlds: the methodological depth of the GHG Protocol and the technical rigor and assurance framework of ISO 14064.

Who can verify an ISO 14064 carbon footprint?

ISO 14064 verification must be carried out by an independent, accredited verification body. These organizations are typically accredited by national accreditation bodies, such as the Deutsche Akkreditierungsstelle (DAkkS) in Germany.

Common verification providers include:

• TÜV SÜD, TÜV NORD, TÜV Rheinland
• LRQA (Lloyd’s Register)
• KPMG Cert
• GUTcert

The verifier reviews your GHG inventory, documentation, data sources, calculation methods, and internal controls. The result is a formal verification statement, which can be used in CSRD reports, ESG disclosures, and stakeholder communications.

How long does ISO 14064 verification take?

The duration of an ISO 14064 verification depends on the size and complexity of the organization, the number of emission sources, and the quality of the underlying data.

As a general guideline:

• Preparation phase (data collection, documentation, internal review): several weeks to months
• Verification process (document review + audit): typically 4–8 weeks
• Total timeline: often 6–12 weeks from verifier engagement to final statement

Companies that rely on automated carbon management platforms and structured data processes are usually able to complete verification significantly faster and with fewer audit findings.

Is ISO 14064 suitable for SMEs?

Yes. ISO 14064 is suitable for both large enterprises and small or medium-sized companies, although the scope and complexity of implementation will differ.

For SMEs:

• ISO 14064-1 can be applied proportionally, focusing on material emission sources
• Verification scope can be tailored to business size and risk
• It provides a strong foundation for customer requests, financing requirements, and future regulation

As CSRD requirements increasingly cascade down supply chains, SMEs that adopt ISO 14064 early gain a competitive advantage and reduce future compliance effort.

What are the biggest challenges when implementing ISO 14064?

Organizations commonly face challenges in:

• Collecting high-quality data across multiple sites and suppliers
• Managing Scope 3 emissions
• Ensuring consistent methodologies over time
• Preparing audit-ready documentation
• Coordinating between sustainability, finance, operations, and procurement teams

These challenges are less about the standard itself and more about process maturity and data management. Digital carbon management solutions can significantly reduce manual effort and error while improving transparency and audit readiness.

How does ISO 14064 support Net-Zero and climate targets?

ISO 14064 provides the data foundation needed to set, monitor, and validate climate targets. Reliable emissions data is essential for:

• Defining realistic reduction pathways
• Tracking progress over time
• Supporting Science-Based Targets
• Demonstrating credibility in Net-Zero commitments

Without standardized, verifiable emissions data, climate targets risk becoming aspirational rather than actionable. ISO 14064 helps ensure that climate strategies are grounded in measurable reality.

Carbmee EIS™ is designed for companies that need more than basic carbon accounting, it’s built for those who require audit-ready, regulator-aligned emissions data that scales across global operations and complex value chains.

By embedding ISO 14064 principles directly into the platform, Carbmee helps organizations close the gap between sustainability ambition and credible, verifiable reporting.

Here’s how Carbmee accelerates your ISO 14064 and CSRD readiness:

• Automates Scope 1, 2, and 3 emission calculations across your entire value chain, including energy use, procurement, logistics, and more
• Provides built-in methodologies aligned with both ISO 14064-1 and the GHG Protocol, ensuring standardized and consistent quantification
• Generates audit-ready documentation and maintains traceability to support external assurance under ISO 14064-3
• Supports full alignment with CSRD and ESRS E1 requirements, including documentation of boundaries, data sources, and emission factors
• Delivers analytics and insights to identify emissions hotspots, track reduction progress, and prioritize decarbonization actions

Whether you’re preparing your first verified carbon footprint or scaling reporting across multiple entities, Carbmee gives you the tools to move from compliance to strategic carbon performance management - all within a single, enterprise-ready platform.