Calculating an organization’s carbon footprint of an organization involves quantifying the greenhouse gas (GHG) emissions associated with its activities. But before beginning the calculation, there is an important decision to make: which methodology or standard to use to prepare the emissions inventory.
Among the most commonly used standards are ISO 14064-1 and the GHG Protocol. Both provide a structured framework for addressing an organization’s GHG emissions, but they are not equivalent and do not set exactly the same requirements.
Understanding these differences is especially important when the information is to be used to meet the requirements of clients, government agencies, or specific programs; to report climate data; or to subsequently submit the carbon footprint for independent verification.
ISO 14064 and the GHG Protocol: What Are They and What Are They Used For?
Both ISO 14064-1 and the GHG Protocol provide recognized frameworks for quantifying and reporting organizations' greenhouse gas emissions.
However, their nature and structure are different.
What is the ISO 14064-1 standard?
ISO 14064-1:2018 is an international standard that establishes principles and requirements at the organizational level for the quantification and reporting of greenhouse gas emissions and removals.
It includes requirements related to the design, development, management, reporting, and verification of an organization's GHG inventory.
The currently valid version is ISO 14064-1:2018, second edition. It was reviewed and approved by ISO in 2024, although a new edition is currently under development that has not yet replaced the 2018 edition.
What is the GHG Protocol?
GHG Protocol (Greenhouse Gas Protocol) is a set of standards and guidelines for accounting for and reporting greenhouse gas emissions.
In the corporate sector, one of its main references is the GHG Protocol Corporate Accounting and Reporting Standard, which establishes a framework for preparing corporate emissions inventories.
One of the best-known features of the GHG Protocol is the classification of emissions into three scopes:
- Scope 1. Direct emissions from sources owned or controlled by the organization, such as the combustion of fuels at specific facilities or in vehicles.
- Scope 2. Indirect emissions associated with the generation of energy purchased and consumed by the organization.
- Scope 3. Other indirect emissions generated throughout the value chain, such as those associated with purchased goods and services, transportation and distribution, waste, business travel, employee commuting, or the use of products sold.
For the latter, the GHG Protocol has a specific standard—the Corporate Value Chain (Scope 3) Standard—which organizes Scope 3 emissions into 15 categories, distinguishing between upstream and downstream activities in the value chain.
ISO 14064 vs. GHG Protocol: Key Differences
The difference between ISO 14064-1 and the GHG Protocol cannot be summarized by saying that one standard is more comprehensive or better than the other. They represent different approaches, and the appropriate standard will depend on the purpose of the inventory and the requirements the organization must meet.
| ISO 14064-1 | GHG Protocol | |
| Nature | ISO International Standard | Set of standards and guidelines |
| Scope | Quantification and Reporting of GHG Emissions and Removals at the Organizational Level | Accounting for and Reporting GHG Emissions |
| Structure | Establishes principles and requirements for developing the organizational inventory | Classify corporate emissions into Scope 1, 2, and 3 |
| Indirect emissions | It establishes requirements for identifying and quantifying significant indirect emissions | It features a specific Scope 3 standard organized into 15 categories |
| Verification | It includes requirements related to inventory verification | Inventories prepared in accordance with the GHG Protocol may also be subject to independent verification |
| Compatibility | It does not have to be used exclusively in place of other GHG programs | It may coexist with other requirements applicable to inventory |
ISO itself states that the ISO 14064 series is neutral with respect to GHG programs and that, when a specific program applies, its requirements are in addition to those established by ISO 14064.
Therefore, framing the issue simply as “ISO 14064 or the GHG Protocol” can lead to a false dichotomy.
Scopes 1, 2, and 3: A Key Difference Between ISO 14064 and the GHG Protocol
One of the issues that causes the most confusion when comparing the two standards is the classification of emissions.
The Scope 1, Scope 2, and Scope 3 framework is specific to the GHG Protocol. In particular, its Scope 3 Standard outlines 15 categories for identifying and organizing indirect emissions across the value chain.
ISO 14064-1:2018 also addresses direct and indirect emissions in an organization’s inventory, but its categories should not be automatically equated with the three scopes of the GHG Protocol.
This difference is particularly significant when a company analyzes the emissions associated with its value chain. Two inventories may be based on similar emission sources, yet structure and report them according to different requirements.
Therefore, before beginning the calculation, it is important to define which standard or methodology will be used and to apply its criteria consistently throughout the entire process.
Can ISO 14064-1 and the GHG Protocol be used together?
Yes, they don't necessarily have to be viewed as mutually exclusive alternatives.
An organization may face different requirements depending on the purpose for which it intends to use its emissions inventory.
For example, you may need to prepare a corporate inventory using the GHG Protocol while also complying with the requirements set forth in ISO 14064-1.
The important thing is to determine from the outset:
- what information the organization needs to obtain and communicate;
- which emissions should be included;
- What are the limits of the inventory?;
- which methodology or program is applicable;
- who will use or receive that information;
- and whether the fingerprint will subsequently be subject to independent verification.
Defining these issues before beginning prevents the need to later reconstruct part of the inventory because the data collected, the boundaries established, or the available evidence do not meet the necessary requirements.
ISO 14064 or the GHG Protocol: Which Should a Company Use?
There is no single answer that applies to all organizations.
The choice should be based primarily on the carbon footprint target and how the information will be used.
If an organization needs to prepare its GHG inventory in accordance with an international standard that establishes principles and requirements for quantification and reporting, ISO 14064-1 provides that framework.
If you are working within the GHG Protocol’s corporate accounting system or need to specifically analyze emissions in your value chain using its 15 Scope 3 categories, you must apply the corresponding GHG Protocol standards.
However, there are situations in which the company does not have a free choice. A customer, a bid, a government agency, a reporting requirement, or a specific program may set the requirements that the inventory must meet.
Therefore, before deciding on a methodology, it is important to ask yourself this question first: Why does the company need to calculate and report its carbon footprint?
The answer will largely determine which requirements you must apply.
The intended use of the footprint also determines its requirements
Not all carbon footprints are calculated for the same purpose.
An organization may need to know its emissions in order to manage its decarbonization strategy internally, respond to demands from customers or its supply chain, participate in certain programs, comply with reporting requirements, or register its carbon footprint in an official registry.
Each of these uses may involve specific conditions.
One example is MITECO’s Registry of Carbon Footprints, Offsets, and CO₂ Removal Projects. To register an organization’s carbon footprint, the Ministry currently requires a minimum scope of Scopes 1 and 2 and also allows for the inclusion of Scope 3. In addition, it requires independent verification of Scope 3 and of Scopes 1 and 2 for organizations that are not SMEs or for SMEs with process emissions. Starting in January 2026, only emissions attributable to the national territory will be eligible for registration.
This example illustrates why the methodology should not be determined in isolation from the intended use of the information.
What role does carbon footprint verification play?
Calculating and verifying a carbon footprint are two different processes.
The calculation makes it possible to quantify and organize the organization's GHG emissions according to a specific methodology.
The verification process includes an independent assessment of the information underlying that inventory. During the process, aspects such as the data used, its traceability, the emission sources considered, the factors applied, the calculations performed, and the application of the relevant criteria are reviewed.
Therefore, if an organization knows that its inventory will need to be verified, it is advisable to take this into account from the very beginning of the calculation process.
It is not enough to simply arrive at a final figure. It is necessary to be able to demonstrate where the data comes from, what criteria were used, and what evidence supports the reported information.
In this regard, having consistent, traceable, and verifiable information enhances the robustness of the inventory and enables third parties to evaluate the climate-related information reported by the organization.
When does a company need to assess its carbon footprint?]
ISO 14064 and the GHG Protocol: Two Evolving Frameworks
The international framework for emissions accounting is evolving.º
In September 2025, the GHG Protocol and ISO announced a strategic allianceto move toward harmonized global standards for GHG accounting and reporting. In July 2026, the GHG Protocol confirmed that both organizations will work on a consolidated global corporate standard that harmonizes the GHG Protocol’s corporate standards and ISO 14064-1.
This does not mean that the current references are no longer valid. ISO 14064-1:2018 remains the current version of the standard while its future revision is being developed.
For companies, this trend points toward greater interoperability among the major international frameworks for accounting and reporting emissions.
The key is not just to choose a standard, but to define the inventory clearly
ISO 14064-1 and the GHG Protocol are two key standards for calculating an organization's carbon footprint, but they are not equivalent and are not necessarily mutually exclusive.
Before beginning the calculation, a company should be clear about what information it needs, what it will use the information for, what requirements it must meet, and who the recipient of that information will be.
From there, you will be able to correctly define the scope of the inventory, the emission sources, the necessary data, and the applicable standard or methodology.
And when that information is to be used by third parties or must meet certain requirements, traceability and the ability to verify the data become particularly important.
Questions Frequently Asked Questions
- ISO 14064-1 is an international standard that establishes principles and requirements for quantifying and reporting GHG emissions and removals at the organizational level. The GHG Protocol is a set of standards and guidelines for accounting for and reporting corporate emissions, and it categorizes emissions into Scope 1, Scope 2, and Scope 3.
- No. Both can be used to work with greenhouse gas inventories, but they differ in nature, structure, and requirements. Nor are they necessarily mutually exclusive.
- The current version is ISO 14064-1:2018, second edition, published in December 2018 and confirmed by ISO in 2024. A new edition is currently under development, but it does not yet replace the 2018 version.
- Scope 1 covers direct emissions from sources owned or controlled by the organization; Scope 2 covers indirect emissions associated with purchased energy; and Scope 3 covers other indirect emissions from the value chain.
- The GHG Protocol organizes Scope 3 emissions into 15 categories, which allow for the classification of indirect emissions generated upstream and downstream of the organization's operations.
- Yes. Using the GHG Protocol to prepare an inventory does not preclude the information from being subsequently subjected to independent verification. The important thing is to determine the criteria and requirements applicable to that verification.