ISO 14064-1 and the GHG Protocol both set the rules for a company carbon footprint and were written to be compatible. The GHG Protocol is free and groups emissions into Scope 1, 2 and 3; ISO 14064-1 is a paid ISO standard with six categories, separate biogenic CO₂ and a documented significance test. ISO 14064-3 covers verification. The two are being merged into one standard, planned for late 2028.
Two standards for the same job
The GHG Protocol and ISO 14064-1 both tell a company how to measure and report its greenhouse gas emissions. The GHG Protocol is published free of charge by the World Resources Institute and the World Business Council for Sustainable Development. ISO 14064-1 is an international standard from the International Organization for Standardization, sold by ISO and national standards bodies. The latest edition of ISO 14064-1 dates from 2018.
They were written to be compatible. A footprint calculated carefully under one can usually be presented under the other with a different grouping and some extra documentation. The choice is mostly about what your readers expect: customers and target-setting schemes tend to ask for the GHG Protocol, while some tenders and national schemes refer to ISO 14064-1, often because they want a verified inventory.
The three parts of ISO 14064
ISO 14064 has three parts, and only the first is about your company footprint.
- ISO 14064-1 sets out how an organisation quantifies and reports its emissions and removals: the inventory itself.
- ISO 14064-2 covers projects that reduce emissions or increase removals, such as the projects behind carbon credits.
- ISO 14064-3 sets out how a footprint or project is verified or validated by a third party.
Where they differ
ISO 14064-1 groups emissions into six categories instead of three scopes: direct emissions, indirect emissions from imported energy, and four categories of other indirect emissions (transport, products the organisation uses, use of the organisation’s products, and other sources). It also asks you to report biogenic CO₂ separately and to document how you decided which indirect emissions are significant enough to include.
The GHG Protocol is more detailed on the value chain. Its Scope 3 standard defines 15 categories with calculation guidance for each, and its Scope 2 guidance sets the rules for location-based and market-based electricity figures.
Verification is not certification
Neither standard is a certificate you buy. When a company says its footprint is ‘ISO 14064 certified’, it usually means a verification body checked the inventory against ISO 14064-1 using the method in ISO 14064-3 and issued a verification statement at a stated level of assurance, limited or reasonable. The verification body itself is accredited under ISO 14065. A GHG Protocol footprint can be verified the same way.
One standard from 2028
In September 2025 the GHG Protocol and ISO announced a partnership to bring their corporate standards together. They plan one co-branded standard that combines the GHG Protocol Corporate Standard, Scope 2 Guidance and Scope 3 Standard with ISO 14064-1, with a public consultation planned for 2027 and publication planned for late 2028. Until then, the existing standards apply, and a well-documented footprint today will carry over.
Doing it in Greener Ahead
Carbon accounting in Greener Ahead calculates your footprint under the GHG Protocol, with Scope 1, Scope 2 location-based and market-based, and all 15 Scope 3 categories, and keeps the emission factor, source and evidence behind every tonne, which is what a verifier checks. It costs €1,495 per year with unlimited users, and you can try it free for 14 days without a card. Check the pricing page for current details.
How the ISO categories map to the scopes
The groupings differ, but every source lands in one place in each.
| ISO 14064-1 category | Examples | GHG Protocol |
|---|---|---|
| 1. Direct emissions and removals | Heating fuel, company vehicles, process emissions, refrigerant leaks | Scope 1 |
| 2. Indirect emissions from imported energy | Purchased electricity, heat, steam and cooling | Scope 2 |
| 3. Indirect emissions from transport | Freight by carriers, business travel, commuting | Scope 3 categories 4, 6, 7 and 9 |
| 4. Indirect emissions from products the organisation uses | Purchased goods and services, capital goods, waste | Scope 3 categories 1, 2, 3 and 5 |
| 5. Indirect emissions from the use of the organisation’s products | Use and end of life of sold products | Scope 3 categories 11 and 12 |
| 6. Other indirect emissions | Anything not covered above | Remaining Scope 3 categories |
What a verifier will ask for
Whichever standard you report under, verification under ISO 14064-3 checks the same things.
- The boundary: which entities and sites are included, and the consolidation approach.
- The source documents behind each activity amount.
- The emission factors used, with their source and edition.
- How excluded sources were judged insignificant.
- Recalculations of the base year and the reasons for them.
Sources and scope
- ISO: ISO 14064-1:2018, organisation-level quantification and reporting
- ISO: ISO 14064-3:2019, verification and validation
- GHG Protocol: Corporate Accounting and Reporting Standard
- GHG Protocol: standards development updates and FAQ
These resources explain a preparation workflow. Check your selected standard and recipient requirements before sharing your report.
Joost ThissenFounder
