ISO 14064-1 vs ISO 14064-3:

Understanding the Key Differences

Why Organizations Are Confused About ISO 14064-1 and ISO 14064-3

Organizations worldwide are under increasing pressure to Measure, Report, and Verify Greenhouse Gas (GHG) Emissions Accurately. As a result, ISO 14064 has become one of the most referenced international standards for carbon accounting and verification.
However, one of the most common questions we encounter is:

What is the difference between ISO 14064-1 and ISO 14064-3 — and which one does my organization actually need?

This article clarifies the distinction, explains how the two standards work together, and helps organizations make informed decisions with confidence.

Understanding the ISO 14064 Family

ISO 14064 is not a single standard but a family of standards designed to support credible greenhouse gas management.
Two parts are especially relevant for organizations:

ISO 14064-1

Focuses on GHG Quantification and Reporting

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ISO 14064-3

Focuses on GHG Verification and Validation

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Although they are closely linked, they serve very different purposes.

What Is ISO 14064-1?

ISO 14064-1 specifies the principles and requirements for Quantifying and Reporting Greenhouse Gas Emissions and Removals at the Organizational Level.

In simple terms:

ISO 14064-1 is about building your carbon footprint correctly.

What ISO 14064-1 Covers

ISO 14064-1 guides organizations on how to:

  • Define organizational and operational boundaries
  • Identify emission sources and sinks
  • Quantify Scope 1, Scope 2, and (where applicable) Scope 3 emissions
  • Select appropriate emission factors
  • Establish a base year
  • Manage data quality and uncertainty
  • Prepare a transparent GHG inventory report

Who ISO 14064-1 Is For

ISO 14064-1 is applicable to:

  • Companies preparing a corporate carbon footprint
  • Organizations responding to regulatory, customer, or investor requirements
  • Entities preparing for ESG reporting
  • Organizations planning future GHG verification

Importantly, ISO 14064-1 does not involve third-party verification. It defines how the organization calculates and reports emissions, not how those emissions are independently confirmed.

What Is ISO 14064-3?

ISO 14064-3 defines the requirements and principles for Verifying and Validating GHG Assertions.

In simple terms:

ISO 14064-3 is about checking whether your carbon footprint is credible.

What ISO 14064-3 Covers

ISO 14064-3 provides a structured framework for:

  • Planning and conducting GHG verification or validation
  • Assessing risks of material misstatement
  • Evaluating data, methodologies, and assumptions
  • Sampling and evidence collection
  • Forming an independent verification opinion
  • Issuing a verification or validation statement

Unlike ISO 14064-1, ISO 14064-3 is used by independent verification bodies, not by organizations themselves.

Who ISO 14064-3 Is For

ISO 14064-3 is relevant to:

  • Organizations seeking independent assurance of their GHG reports
  • Companies responding to regulators, investors, or customers
  • Projects or organizations participating in carbon markets
  • Any entity needing credible, third-party verified emissions data

How ISO 14064-1 and ISO 14064-3 Work Together

A common misconception is that organizations must choose one or the other. In reality, they are designed to work together.

A typical pathway looks like this:

1. Implement ISO 14064-1

The organization quantifies emissions and prepares a GHG inventory.

2. Engage ISO 14064-3 Verification

An independent body verifies the GHG report in accordance with ISO 14064-3.

3. Issue a Verified GHG Statement

The organization receives a formal verification statement confirming credibility.