ISO 14064-1 Requirements: 6 Categories and the GHG Protocol

What is ISO 14064-1 and how is it structured?

ISO 14064-1:2018 is the international standard that sets principles and requirements, at the organization level, for quantifying and reporting greenhouse gas (GHG) emissions and removals. It covers the design, development, management, reporting and verification of an organization’s GHG inventory.

Its full title is “ISO 14064-1:2018 — Greenhouse gases — Part 1: Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals”. It is the second edition, published in December 2018 by subcommittee ISO/TC 207/SC 7, and it cancelled and replaced the first edition, ISO 14064-1:2006. ISO reviewed and confirmed it in 2024. The text runs to 47 pages and is available in English, French and Spanish.

Two points in the scope matter in practice. The ISO 14064 series is independent of any GHG programme: if a programme applies to you (a regulatory scheme, a voluntary registry, a customer’s questionnaire), its requirements come on top of the standard’s. And ISO 14064-1 covers the organization: the carbon footprint of a product falls under ISO 14067:2018.

This guide is about the standard itself. For the service, from scoping to verification readiness, see our page on GHG inventories to ISO 14064.

The clauses of the standard

The table of contents is public on ISO’s preview platform. Requirements sit in clauses 4 to 10; the annexes give guidance.

What changed from ISO 14064-1:2006

According to the foreword of the 2018 edition, the main changes are: a new approach to reporting boundaries that makes it easier to include indirect emissions across the value chain; the category “other indirect GHG emissions” renamed “indirect GHG emissions”, with requirements to classify them into five specific categories; “operational boundaries” renamed “reporting boundaries”; and new requirements on biogenic carbon and on emissions related to electricity.

Document, explain, justify

The introduction defines three verbs used throughout the requirements. To document is to record the information in writing. To explain is to describe how an approach was applied and why it was chosen. To justify adds why the alternatives were not chosen, with the supporting data or analysis. A conforming inventory is, first of all, a written file.

Which principles and boundaries does ISO 14064-1 set?

The standard rests on five principles, relevance, completeness, consistency, accuracy and transparency, and requires two boundaries: organizational (which entities and sites) and reporting (which emissions and removals). These are the same foundations as the GHG Protocol.

The five principles

These are the headings of clause 4 of ISO 14064-1:2018. The GHG Protocol Corporate Standard, revised edition of 2004, uses the same five principles, and its freely available definitions show what they demand:

The organizational boundary

It states which entities and sites are in the inventory. The standard’s public definitions refer to two families of approach, equity share or control (financial or operational), and Annex A describes how to consolidate data under either. For an SME that wholly owns all its sites, the choice changes nothing; it matters as soon as there is a joint venture, a shared subsidiary or a leased site. The choice is written down, justified and kept from year to year.

The reporting boundary

It states which emissions and removals are quantified and reported. A direct emission comes from a source the organization owns or controls: boiler, furnace, generator, vehicles, process, refrigerant leaks. An indirect emission is a consequence of its activities but comes from sources it does not own or control, generally upstream or downstream in its chain. The standard also counts removals, the withdrawal of GHGs from the atmosphere by sinks the organization owns or controls, and deals separately with biogenic carbon (Annex D) and electricity (Annex E).

What are the 6 categories of ISO 14064-1 and how do they map to scopes 1, 2 and 3?

ISO 14064-1:2018 organizes the inventory into six categories: one for direct emissions and removals and five for indirect emissions. Category 1 matches GHG Protocol scope 1, category 2 matches scope 2, and categories 3 to 6 share what the GHG Protocol calls scope 3.

The titles below are those of Annex B of the standard (“Direct and indirect GHG emissions categorization”), as published by ISO in its table of contents.

The standard splits category 4 into goods purchased and services used. GHG Protocol categories 3 (fuel- and energy-related activities), 5 (waste generated in operations), 8 (upstream leased assets), 10 (processing of sold products), 13 (downstream leased assets), 14 (franchises) and 15 (investments) are not in this table: their assignment to one of the six ISO 14064-1 categories falls under Annex B of the standard, of which the free iso.org preview only shows the headings. Read it in the text of the standard before drawing up your correspondence table.

Moving from one presentation to the other does not require two calculations. It requires a written mapping, line by line, tied to the same data file. That is what your European customers, who almost all think in scopes, and a verifier working to ISO 14064-1 will then read.

How do you decide that an indirect emission is significant?

By first stating what the inventory is for, then setting significance criteria consistent with that use, and applying them line by line. Annex H of the standard describes the process in four steps:

1. identify the intended use of the inventory (ESG report, customer request, lender, reduction target);
2. define criteria to evaluate the significance of indirect emissions, consistent with that use;
3. identify and evaluate the indirect emissions;
4. apply the criteria to select the significant indirect emissions.

The criteria are yours. The GHG Protocol Scope 3 Standard suggests some you can draw on: estimated size, influence (can you act on it?), risk, stakeholder expectations, outsourced activities. Whatever is excluded is explained and justified in the standard’s sense. European customers ask for these figures because they sit in their own value chain; our article on CSR in Morocco in 2026-2027 for exporters explains what a CSRD customer can and cannot demand.

How does ISO 14064-1 handle the base year, data quality and uncertainty?

The standard devotes sub-clause 6.4 to selecting and establishing a base year and to reviewing the base-year inventory, and clause 8 to inventory quality management, including uncertainty assessment. These are the three points that make figures comparable year after year.

The base year

It is the year every later year is compared against. The GHG Protocol Corporate Standard requires a year for which verifiable data exist, a justified choice and a written recalculation policy: a significant structural change (acquisition, divestment, outsourcing), a change of method or emission factors, or a significant error triggers a recalculation; organic growth or decline does not. You set the significance threshold; write it down before the first report. Our page on GHG inventories to ISO 14064 sets out these rules.

One point deserves attention in 2026: the future joint GHG Protocol–ISO standard will change methods. A recalculation policy that already covers a “change of standard” saves you from starting over.

Data quality

Clause 8 covers GHG information management, document retention and record keeping. In practice: every activity data point (kWh, litres, tonnes, tonne-kilometres) links to evidence, an invoice, a meter reading, a delivery note or the refrigerant log; every emission factor is cited with its source, year and region; every estimate follows a written rule. Annex C gives guidance on site-specific data: analyses and sampling, laboratories, calibration, data gaps.

Uncertainty

Sub-clause 8.3 deals with assessing uncertainty. The GHG Protocol separates scientific uncertainty, which comes from incomplete knowledge of the processes, from estimation uncertainty, which arises whenever an emission is calculated from data and factors. The second is the one you can reduce: better data, calibrated meters, supplier-specific data. Higher uncertainty on indirect emissions is acceptable as long as it is known and disclosed.

What goes into the GHG report, and what does ISO 14064-3 verification add?

The GHG report is the document the organization publishes or hands to a third party to present its inventory; the standard distinguishes required, recommended and optional information (sub-clause 9.3), and Annex F proposes a structure. Verification under ISO 14064-3:2019 adds an independent third party’s opinion on that statement.

The GHG report

The exact list of required information is in sub-clause 9.3.1 of the paid text. A report that lets a reader redo the calculation describes at least: the organization and its consolidation approach, the period covered, the base year and recalculation policy, emissions by category (and by scope if your recipients ask), removals and biogenic carbon reported separately, significance criteria and justified exclusions, methods and factors, the uncertainty assessment, year-on-year changes, and whether it was verified, by whom and at what level of assurance. Plan it (sub-clause 9.2) before collecting data: the intended use sets the content.

Verification

ISO 14064-1 does not say how to verify: its clause 10 only describes the organization’s role in verification. Three other standards in the family take over:

The principles of ISO 14064-3:2019 are impartiality, an evidence-based approach, fair presentation, documentation and conservativeness. The standard provides for a reasonable or limited level of assurance (Annex A deals with limited-assurance verifications) and four outcomes: unmodified opinion, modified opinion, adverse opinion, or disclaiming the issuance of an opinion. Verification does not “certify” the company: it gives an opinion on a statement, for a period.

Whoever prepared the inventory cannot verify it. ACG scopes, calculates, documents, trains and runs a mock review; an independent, accredited body verifies.

Is ISO 14064-1 being revised, and what does the joint standard with the GHG Protocol change?

Yes. On 11 November 2026, iso.org shows ISO 14064-1:2018 at stage 90.92 (“to be revised”) and a draft third edition, ISO/WD 14064-1.2, at stage 20.60 (close of comment period). The 2018 edition remains in force and the content of the future edition has not been published.

In parallel, the GHG Protocol announced on 29 July 2026 that it and ISO will combine their corporate standards into a single co-branded standard. The consolidation brings together the GHG Protocol Scope 1, Scope 2, Scope 3 and Actions and Market Instruments standards with ISO 14064-1. Its development plan of 29 July 2026 calls it “Corporate Standard Version 3.0”: integrated public consultation estimated for Q2 2027, publication estimated for Q4 2028. Nothing has been published yet.

What if you start now?

Start, on the texts in force. A European customer, a lender or an importer will not give you two years’ grace. Three precautions make the inventory durable:

• calculate once, on a single data set, and produce both presentations (ISO categories and scopes) through a mapping table;
• write into the recalculation policy that a change of standard triggers a recalculation of the base year;
• keep each activity data point separate from its emission factor, so you can recalculate under new rules without collecting again.

Your customers’ sustainability reporting is often the first use of the inventory; our ESG and CSR page maps the requests you are likely to receive. The reduction plan that follows the inventory belongs to our decarbonisation strategy page; if an importer asks for installation-level emissions, see CBAM for exporters: it is a separate calculation.

Before starting an ISO 14064-1 inventory: what should you check?

Before collecting anything, write down what the inventory is for, who will read it and what each reader expects. The points below avoid redoing the work the following year.

• The intended use of the inventory is written down: customer, lender, ESG report, reduction target, verification.
  
• Recipients and their formats are known: ISO categories, GHG Protocol scopes, a customer questionnaire.
  
• The text of ISO 14064-1:2018 has been bought and read by the person leading the inventory.
  
• The organizational boundary and consolidation approach are chosen and justified.
  
• Each site has a list of its direct emission sources, refrigerants and generators included.
  
• Significance criteria for indirect emissions are written and consistent with the intended use.
  
• A mapping table between the 6 ISO categories and scopes 1, 2 and 3 is planned.
  
• The base year is chosen, and the recalculation policy covers a change of standard.
  
• An owner, a source and supporting evidence are assigned to each data point.
  
• An emission factor register (source, year, region) is open.
  
• The uncertainty assessment method is chosen.
  
• The level of assurance your recipients expect is known, if they require verification.
  
• Someone who does not do the calculation is assigned to review it.