ISO 14064: A Practical Guide to GHG Quantification, Reporting and Verification

2nd Sep, 2026

Climate reporting is moving from broad sustainability statements to measurable emissions data. Organizations are increasingly expected to know where their greenhouse gas (GHG) emissions come from, how much they generate and how their reported figures can be supported with reliable evidence.

This is where the ISO 14064 standard becomes relevant. It provides a structured framework for quantifying, reporting and verifying greenhouse gas emissions and removals at organizational and project levels.

But understanding ISO 14064 requires more than knowing its definition. Organizations need to understand which part of the standard applies to them, how a GHG inventory is developed, how Scope 1, Scope 2 and Scope 3 emissions fit into the process and what is involved in verification.

This guide explains ISO 14064-1, ISO 14064-2 and ISO 14064-3, the practical process of GHG quantification and reporting, common implementation challenges and how organizations can prepare for credible GHG reporting and verification.

What Is ISO 14064?

ISO 14064 is a series of international standards focused on greenhouse gas quantification, reporting, validation and verification.

The series addresses GHG information at different levels:

• ISO 14064-1 focuses on organizations and their GHG inventories.
• ISO 14064-2 focuses on GHG projects designed to reduce emissions or increase removals.
• ISO 14064-3 focuses on the validation and verification of GHG statements.

This structure is important because an organization developing its annual GHG inventory has a different requirement from a company assessing the impact of a specific emission-reduction project.

At the organizational level, ISO 14064-1 provides requirements and guidance for designing, developing, managing, reporting and verifying a GHG inventory. It helps organizations establish a consistent approach to identifying relevant emission sources and removals, quantifying emissions and communicating the resulting information.

The value of the standard lies in creating a traceable process. Instead of reporting a single carbon figure without context, an organization can establish where the number came from, what data was used, how calculations were performed and how the information was reviewed.

What Are the Three Parts of ISO 14064?

Understanding the three parts is the first step in determining how ISO 14064 requirements relate to your organization.

Standard	Primary Focus	Typical Application
ISO 14064-1	Organizational GHG inventory	Quantification and reporting of organizational emissions and removals
ISO 14064-2	GHG projects	Quantification and monitoring of emission reductions or increased removals from projects
ISO 14064-3	Validation and verification	Validation or verification of GHG statements and related information

ISO 14064-1: Organizational GHG Emissions and Removals

ISO 14064-1 is relevant when an organization wants to develop and report its GHG inventory.

It provides a structured basis for identifying emission sources and removals, establishing inventory boundaries, quantifying GHG emissions, managing the inventory and preparing the resulting GHG statement.

For example, a manufacturing company may use ISO 14064-1 to account for emissions associated with fuel consumption, purchased electricity, industrial processes, refrigerants and relevant indirect sources.

The important point is that the inventory should be based on defined boundaries and documented data rather than an estimated figure created only for reporting purposes.

ISO 14064-2: GHG Projects

ISO 14064-2 addresses GHG projects rather than the organization’s complete corporate inventory.

A project could involve an initiative intended to reduce emissions or increase GHG removals. Examples may include an energy-efficiency project, renewable-energy initiative, methane-reduction project or activity designed to increase carbon removals.

The focus is on establishing the project’s baseline, quantifying the change in GHG emissions or removals and monitoring and reporting the results. This makes ISO 14064-2 particularly relevant when an organization needs to demonstrate the GHG impact of a specific project rather than simply report its overall organizational emissions.

ISO 14064-3: GHG Validation and Verification

ISO 14064-3 addresses the process used to validate or verify GHG statements and related information. This becomes important when an organization needs greater confidence in the reliability of its reported GHG information.

Verification involves examining the GHG statement, supporting information, data, calculations and relevant processes against defined criteria.

In simple terms:

ISO 14064-1 helps establish the inventory.
ISO 14064-2 addresses GHG projects.
ISO 14064-3 provides the framework for validation and verification.

How to Develop a GHG Inventory Under ISO 14064-1

Developing a credible organizational GHG inventory is not simply a matter of collecting energy bills and converting them into tonnes of CO₂e. The organization first needs to establish what is included, identify relevant emission sources, select appropriate calculation methods and maintain evidence for the reported figures.

A practical GHG inventory process can be approached through the following stages.

1. Define Organizational and Reporting Boundaries

Before calculating emissions, determine which operations, facilities, assets and activities are included in the inventory.

For organizations with multiple sites or business units, this step can become particularly important. The boundary should be clearly defined so that emissions are not accidentally omitted, counted twice or assigned inconsistently.

The reporting period should also be established. Using a consistent reporting period makes year-on-year comparison more meaningful.

2. Identify GHG Emission Sources and Removals

Once the boundary is established, identify the sources that generate GHG emissions and any relevant activities that result in GHG removals.

For a manufacturing organization, sources may include:

• Stationary fuel combustion
• Company-owned vehicles
• Industrial processes
• Refrigerant leakage
• Purchased electricity
• Relevant upstream and downstream activities

The objective is to create a complete picture of the organization’s relevant GHG sources rather than focusing only on the easiest data to obtain.

3. Collect Activity Data

The next step is gathering the information required for GHG emissions calculation.

Examples of activity data include:

• Electricity consumed in kWh
• Diesel consumed in litres
• Natural gas consumed in a defined unit
• Refrigerant quantities
• Fuel used by company vehicles
• Relevant transportation or business-travel activity
• Purchased materials or services, where applicable

Data may come from utility bills, fuel records, production systems, purchase records, meters, logistics records or other operational sources. The quality of the final inventory depends heavily on the quality and consistency of this underlying data.

4. Select Emission Factors and Calculation Methods

Activity data alone does not provide the organization’s total emissions. It needs to be converted into an appropriate GHG quantity using a suitable calculation method and emission factor.

A simplified calculation can be represented as:

Activity Data × Emission Factor = GHG Emissions

For example, electricity consumption can be combined with an appropriate electricity emission factor to estimate the associated emissions.

However, emission factors should not be selected simply because they are convenient. Their applicability, source, geographic relevance, time period, units and underlying assumptions should be considered and documented.

5. Calculate GHG Emissions

After collecting the required activity data and selecting suitable calculation methods, the organization can quantify emissions for its identified sources.

The results are generally expressed in carbon dioxide equivalent (CO₂e) so that different greenhouse gases can be represented on a comparable basis.

Calculations should be traceable. An organization should be able to connect the final reported number back to its original activity data, calculation method, emission factor and supporting records.

6. Review Data Quality and Uncertainty

Not every GHG data point will have the same level of accuracy. Some information may come directly from meters, while other figures may rely on invoices, estimates, supplier information or assumptions. Recognizing these differences is important when assessing the quality of the inventory.

Organizations should establish appropriate checks to identify:

• Missing data
• Unusual changes
• Calculation errors
• Inconsistent units
• Duplicate information
• Unsupported assumptions

Where estimation is necessary, the basis for the estimate should be documented rather than hidden within the final number.

7. Compile and Report the GHG Inventory

The final stage is bringing the calculations and supporting information together into a structured GHG inventory and statement.

Reporting should provide sufficient information for users to understand what has been included, how emissions were quantified and what limitations or relevant assumptions apply.

A well-maintained inventory should also support future reporting. If the same activity data, boundaries, calculation methods and records are maintained consistently, organizations can make more meaningful comparisons over time.

Scope 1, Scope 2 and Scope 3 Emissions Explained

Scope 1, 2 and 3 are commonly used GHG accounting categories, while ISO 14064-1 provides the organizational framework for identifying and quantifying relevant emissions and removals.

Scope 1 – Direct GHG Emissions

Scope 1 covers direct emissions from sources owned or controlled by the organization.

Common examples include:

• Fuel burned in company-owned boilers
• Fuel used in organization-owned vehicles
• Emissions from industrial processes
• Fugitive emissions such as refrigerant leakage

For example, if a manufacturing facility operates a natural-gas-fired boiler, the emissions from that fuel combustion would generally fall within its direct emissions.

Scope 2 – Indirect Emissions from Purchased Energy

Scope 2 relates to indirect emissions associated with purchased energy consumed by the organization.

Purchased electricity is the most common example. If a factory purchases electricity from the grid, the physical emissions occur at the energy-generation source rather than inside the factory. The emissions associated with the organization’s purchased electricity are therefore treated as indirect energy-related emissions.

Depending on the organization’s energy profile, purchased steam, heat or cooling may also be relevant.

Scope 3 – Other Indirect Value-Chain Emissions

Scope 3 covers other indirect emissions occurring across relevant activities in an organization’s value chain.

Depending on the organization, these may include:

• Purchased goods and services
• Transportation and distribution
• Business travel
• Employee commuting
• Waste-related activities
• Use of sold products
• Other relevant upstream or downstream activities

Scope 3 can be more challenging because the required information may sit outside the organization’s direct operational control.

For example, a manufacturer may have reliable electricity and fuel records but limited primary data from suppliers or logistics providers. This is why Scope 3 inventories often require greater coordination, data assessment and the use of appropriate estimation methods.

How Are GHG Emissions Calculated?

At a basic level, GHG emissions calculation involves connecting an organization’s activity to the emissions associated with that activity.

The simplified concept is:

Activity Data × Emission Factor = Estimated GHG Emissions

For example:

If a facility consumes 10,000 kWh of electricity and the applicable emission factor is 0.7 kg CO₂e/kWh, the resulting emissions would be 7,000 kg CO₂e, or 7 tCO₂e.

Consider electricity consumption as an example. If a facility records its annual electricity consumption, that activity data can be combined with an applicable electricity emission factor to calculate the associated emissions.

The same approach can be applied to other sources:

Activity	Typical Data
Electricity	kWh consumed
Diesel	Litres consumed
Natural gas	Quantity consumed
Refrigerants	Quantity leaked/replenished
Business travel	Distance or travel activity
Transportation	Distance, fuel, weight or other relevant activity data

In practice, GHG accounting can become considerably more complex when an organization operates multiple facilities, uses different fuels, has process emissions or needs to quantify indirect value-chain emissions.

This is why calculation methodology, emission-factor selection, data quality, unit consistency and documentation are all important parts of a credible inventory.

ISO 14064 vs GHG Protocol: What Is the Difference?

ISO 14064 and the GHG Protocol are not simply competing approaches. They are widely used frameworks for addressing GHG accounting and reporting, but they have different structures and purposes.

ISO 14064 is a standards series covering organizational GHG inventories, GHG projects and validation and verification.

The GHG Protocol provides widely used frameworks and guidance for measuring and reporting GHG emissions, including corporate and value-chain accounting.

Organizations should therefore consider their reporting objective, stakeholder expectations, applicable requirements and need for verification when deciding how to structure their GHG accounting approach.

In some cases, organizations may use GHG Protocol guidance alongside an ISO-based approach rather than treating the two as mutually exclusive.

When Should an Organization Use ISO 14064?

ISO 14064 can be relevant when an organization needs a structured approach to its GHG information and wants stronger control over how emissions are quantified and reported.

It may be particularly useful when an organization wants to:

• Establish an organizational GHG inventory
• Measure and understand its carbon footprint
• Respond to customer requests for emissions information
• Support ESG and sustainability reporting
• Establish a baseline for emission-reduction programmes
• Improve the reliability of reported GHG information
• Prepare for independent GHG emissions verification
• Demonstrate a more structured approach to GHG accounting

The need for ISO 14064 should ultimately be assessed against the organization’s reporting objectives, stakeholder requirements, business activities and applicable regulatory or contractual expectations.

Common Challenges in ISO 14064 GHG Inventory Preparation

Developing a GHG inventory often becomes difficult not because the calculation itself is complicated, but because organizations struggle to obtain consistent and traceable information.

1. Incomplete Activity Data: Different departments may maintain energy, fuel, transportation, production or purchasing information in different formats. Missing months or inconsistent units can affect the final inventory.

2. Selecting Appropriate Emission Factors: Using an emission factor without checking its applicability can affect the credibility of the calculation. Organizations need a documented basis for the factors used.

3. Defining Organizational Boundaries: Organizations with multiple sites, leased assets, joint operations or complex structures may find it difficult to determine what should be included in the inventory.

4. Managing Scope 3 Data: Value-chain emissions often require information from suppliers, logistics providers, employees, customers or other external sources. Primary data may not always be available.

5. Maintaining Traceable Calculation Records: A final emissions figure should be supported by the underlying activity data, emission factor, calculation method and relevant records. Poor traceability can make review and verification difficult.

6. Preparing Evidence for Verification: Organizations may calculate their emissions correctly but still struggle to demonstrate the basis of their calculations. Verification readiness therefore requires organized records, clear methodologies and evidence that can be traced back to the reported results.

Benefits of ISO 14064 for Organizations

A structured ISO 14064 approach can provide organizations with more than a reported carbon figure.

Key benefits include:

• Better visibility: Identify where significant GHG emissions are generated.
• More reliable data: Establish consistent methods for collecting and calculating emissions.
• Stronger reporting: Support credible sustainability and GHG disclosures.
• Better decision-making: Use emissions data to identify reduction opportunities.
• Improved verification readiness: Maintain the evidence and traceability needed for independent review.
• Greater stakeholder confidence: Provide more structured and transparent GHG information.

For organizations beginning their decarbonization journey, a reliable inventory can also provide the baseline needed to set priorities and track progress over time.

How 4C Consulting Can Help with ISO 14064

Developing a reliable GHG inventory requires more than understanding the standard. Organizations also need to translate requirements into practical data collection, calculation, reporting and review processes.

4C Consulting can support organizations through areas such as:

• ISO 14064 gap assessment
• GHG inventory development
• Organizational boundary assessment
• GHG data collection and calculation support
• GHG documentation and reporting
• ISO 14064 training
• Verification-readiness support
• Improvement of GHG accounting processes

Our approach focuses on helping organizations establish a practical and traceable GHG management process that fits their operations and reporting objectives.

Want to strengthen your GHG accounting process?

Connect with 4C Consulting to discuss your ISO 14064 requirements and GHG inventory needs.

FAQs About ISO 14064

1. What is ISO 14064 used for?

ISO 14064 is used to support the quantification, reporting, validation and verification of greenhouse gas emissions and removals at organizational and project levels, depending on the applicable part of the series.

2. What is ISO 14064-1?

ISO 14064-1 focuses on GHG inventories at the organizational level. It addresses areas including the development, management, reporting and verification of an organization’s GHG inventory.

3. What is the difference between ISO 14064-1, 14064-2 and 14064-3?

ISO 14064-1 focuses on organizational GHG inventories, ISO 14064-2 addresses GHG projects and ISO 14064-3 provides principles and requirements for validation and verification of GHG statements.

4. Does ISO 14064 cover Scope 1, Scope 2 and Scope 3 emissions?

ISO 14064-1 addresses organizational GHG inventories, within which organizations identify and quantify relevant direct and indirect emissions. Scope classifications are commonly used in GHG accounting to distinguish direct emissions, purchased-energy emissions and other value-chain emissions.

5. How are GHG emissions calculated under ISO 14064?

GHG emissions are generally quantified using appropriate activity data and calculation methods, often involving an emission factor. The selected methodology, data sources, assumptions and calculations should be documented and traceable.

6. What is ISO 14064 verification?

ISO 14064 verification is the process of independently assessing a GHG statement and relevant supporting information against defined criteria. ISO 14064-3 provides the framework for validation and verification activities.

7 Is ISO 14064 certification required?

ISO 14064 does not function as a conventional management-system certification standard like ISO 9001 or ISO 14001. Organizations may use ISO 14064-1 to develop their GHG inventory, while independent verification may be pursued when required by customers, reporting frameworks, contractual commitments, or other business needs.

8. Who needs ISO 14064?

Organizations that need to quantify and report their GHG emissions, establish a credible GHG inventory, support sustainability reporting, respond to stakeholder requirements or prepare for independent verification may benefit from an ISO 14064-based approach.

9. What records are needed for ISO 14064 verification?

Records can include activity data, energy and fuel records, emission factors, calculation sheets, boundary information, methodologies, assumptions, supporting documents and evidence of internal review. The exact evidence required depends on the inventory and verification scope.