Scope 3 of the GHG Protocol: the 15 categories explained

Scope 3 of the GHG Protocol groups together all the indirect emissions of a company's value chain, from its suppliers to the use and end of life of its products. It is the hardest part to measure and, almost always, the largest part of the emissions inventory.

While Scope 1 and 2 cover direct emissions and energy consumption, Scope 3 covers everything that happens outside the organization's boundaries but as a consequence of its activity.

According to the Carbon Disclosure Project (CDP), supply chain emissions are, on average, around 11.4 times higher than the operational emissions (Scopes 1 and 2) of reporting companies. In sectors such as fashion, automotive or food, Scope 3 can concentrate the vast majority of the carbon footprint.

In this guide we explain the 15 Scope 3 categories defined by the GHG Protocol, with concrete examples and recommendations to calculate and reduce them rigorously.

If you want to place this calculation within the Spanish framework, our guide on the MITECO carbon footprint registry and the Calculo, Reduzco and Compenso seals can help.

What is Scope 3 and why is it decisive?

Scope 3 includes all the greenhouse gas emissions that the company does not directly control, but which are generated along its value chain: purchasing, transport, use of sold products, waste treatment, investments and more.

Its relevance is twofold. On the one hand, the CSRD requires large companies to report their full footprint, Scope 3 included, within the ESRS standards. The Omnibus package approved at the end of 2025 has raised the thresholds and deferred the entry deadlines (the new scope applies to financial years starting on or after 1 January 2027), but Scope 3 remains a central part of the report. On the other hand, investors and large clients increasingly demand transparency: ignoring Scope 3 means being left out of international supply chains that are becoming ever more demanding.

What are the 15 Scope 3 categories of the GHG Protocol?

The GHG Protocol, in its Corporate Value Chain (Scope 3) standard, classifies Scope 3 into 15 categories, divided between upstream activities (linked to purchasing) and downstream activities (linked to the sale and use of products).

1. Purchased goods and services

This covers the emissions of producing the goods and services the company buys. A furniture manufacturer, for example, must account for the emissions of growing, logging and processing the wood. The challenge is obtaining reliable data from suppliers; the recommendation is to request verified carbon footprint reports from the supply chain.

2. Capital goods

Emissions from manufacturing assets that last more than a year (buildings, machinery, vehicles). A company that builds a new plant must include the footprint of the materials and the construction process. In industry, this category tends to be very relevant.

3. Fuel- and energy-related activities

This covers the emissions from the extraction, production and transport of the fuels and energy the company consumes and that are not already in Scopes 1 and 2. For example, the transport of natural gas before it reaches the factory, or electricity grid losses.

4. Upstream transportation and distribution

The transport of the purchased goods from the supplier to the company. In a textile company, the maritime transport of fabrics from Asia falls here. It is advisable to work with logistics operators that provide emissions data in line with frameworks such as ISO 14083 or the GLEC Framework.

5. Waste generated in operations

Emissions from treating and disposing of the waste from the company's own activity (not from the products sold). An example is the methane released at a landfill by a factory's waste.

6. Business travel

Employee travel for work purposes. If the sales team flies frequently, those emissions must be accounted for, usually from the distance travelled and the mode of transport.

7. Employee commuting

The daily transport of workers between home and the workplace. The impact grows in large workforces and at sites far from public transport. Sustainable mobility plans (remote working, car sharing, public transport incentives) can significantly reduce these emissions.

8. Upstream leased assets

Emissions from assets the company uses but does not own, such as rented buildings or leased machinery. A company in rented offices must account for the footprint of that building's energy consumption.

9. Downstream transportation and distribution

The transport of the sold products to the end customer. In e-commerce, last-mile delivery is one of the main sources in this category.

10. Processing of sold products

If the products require transformation before reaching the consumer, those emissions also count. A steel supplier must account for the footprint generated when its steel is turned into cars or structures.

11. Use of sold products

This can be enormous in automotive or home appliances. It includes the emissions of the entire service life of the product in the customer's hands. A manufacturer of combustion cars must account for the fuel its vehicles consume over years.

12. End-of-life treatment of sold products

Emissions from the moment the sold products become waste. A packaging company must include, for example, the methane from plastics sent to landfill.

13. Downstream leased assets

When the company leases an asset to a third party, it accounts for the emissions of the lessee's use. A real estate company that rents offices includes the energy consumed by its tenants.

14. Franchises

If the company operates through franchises, it accounts for the emissions of those establishments. A restaurant chain with franchises in several cities measures its full footprint this way.

15. Investments

The emissions associated with the company's investments. Banks, insurers and funds are especially responsible for this category, as they must measure the financed emissions of the companies they invest in.

Practical strategies for managing Scope 3

The biggest obstacle of Scope 3 is gathering reliable data across the value chain. To tackle it, companies can combine several strategies:

1. Collaboration with suppliers and customers: joint emissions reporting programmes and data clauses in contracts.
2. Sector-specific databases: where there is no primary data, fall back on recognised emission factors.
3. Digitalisation: platforms that collect and update the information continuously.
4. Prioritising categories: start with the categories that weigh most in the emissions inventory (materiality analysis).
5. Shared reduction targets: align goals with the key partners in the chain, ideally with science-based targets (SBTi).

Scope 3: a thermometer of corporate sustainability

Scope 3 concentrates most of the emissions and demands a profound change in the relationship with suppliers, customers and investors. The 15 categories of the GHG Protocol provide the structure to address it rigorously.

Companies that integrate it seriously not only reduce their footprint, they also gain resilience and market access. To go deeper, our guide on how to overcome the supplier data barrier in Scope 3 can help.

If you need to calculate and maintain your Scope 3 inventory continuously, you can rely on a carbon footprint management tool.

Frequently asked questions about Scope 3

Is it mandatory to report Scope 3 in Spain?

For large companies subject to the CSRD, Scope 3 is part of the report when it is material. It is also necessary to register with the MITECO carbon footprint registry with ambitious reduction targets.

Which categories are most relevant?

It depends on the sector: in automotive, the use of sold products usually dominates; in food, purchased goods; in services, travel and commuting.

Can estimates be used?

Yes, as long as they are based on recognised emission factors and follow the GHG Protocol methodology. The ideal is to progressively replace estimates with primary supplier data.