> ## Documentation Index
> Fetch the complete documentation index at: https://docs.matproof.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Scope 3 GHG Calculations

> How Matproof calculates Scope 3 greenhouse gas emissions from supplier data.

## What is Scope 3?

Scope 3 emissions are **indirect GHG emissions** that occur in a company's value chain — both upstream (suppliers) and downstream (customers, product use, end-of-life).

Under **ESRS E1-6**, CSRD reporters must disclose Scope 3 emissions across all relevant GHG Protocol categories.

## The 15 Scope 3 categories

| Category                         | Type       | Typical data source               |
| -------------------------------- | ---------- | --------------------------------- |
| 1. Purchased goods & services    | Upstream   | Supplier spend + emission factors |
| 2. Capital goods                 | Upstream   | Asset purchases                   |
| 3. Fuel & energy-related         | Upstream   | Energy supplier data              |
| 4. Upstream transportation       | Upstream   | Logistics provider data           |
| 5. Waste generated in operations | Upstream   | Waste handler data                |
| 6. Business travel               | Upstream   | HR / travel booking               |
| 7. Employee commuting            | Upstream   | Employee survey                   |
| 8. Upstream leased assets        | Upstream   | Lease agreements                  |
| 9. Downstream transportation     | Downstream | Customer delivery data            |
| 10. Processing of sold products  | Downstream | Customer data                     |
| 11. Use of sold products         | Downstream | Product performance data          |
| 12. End-of-life treatment        | Downstream | Industry averages                 |
| 13. Downstream leased assets     | Downstream | Lease data                        |
| 14. Franchises                   | Downstream | Franchisee data                   |
| 15. Investments                  | Downstream | Financial data                    |

## Calculation methods in Matproof

Matproof supports the three GHG Protocol calculation methods:

### Spend-based method

Uses supplier spend × sector-specific emission factors.

* **Best for:** First-year reporting, when supplier data is unavailable
* **Data needed:** Spend by category, country
* **Emission factors:** Exiobase + DEFRA databases (updated annually)

### Activity-based method

Uses physical activity data × emission factors.

* **Best for:** High-spend categories where accuracy matters
* **Data needed:** Quantities (kg, km, kWh, etc.) from suppliers
* **More accurate** than spend-based

### Supplier-specific method

Uses actual emissions data reported by suppliers.

* **Best for:** Key suppliers with robust carbon accounting
* **Data needed:** Supplier's verified Scope 1 + 2 emissions, allocated to your share
* **Most accurate** — preferred by auditors

## Setting up Scope 3 in Matproof

1. **Go to CSRD → Scope 3**
2. **Select which categories are material** (based on your DMA results)
3. **Choose calculation method per category**
4. **Map your supplier data** — either from questionnaire responses or manual input
5. **Review calculations** — Matproof shows the math and data sources
6. **Export** — results mapped to ESRS E1-6 disclosure requirements

## Collecting data from suppliers

The supplier questionnaire includes Scope 3 data request fields:

* For **spend-based**: Matproof uses your procurement data automatically
* For **activity-based**: Questionnaire asks for quantities (e.g., "How many tonnes of goods did you deliver to us?")
* For **supplier-specific**: Questionnaire asks for their verified Scope 1+2 emissions and revenue attribution

## Emission factors

Matproof uses the following emission factor databases:

* **Exiobase** — multi-regional input-output tables (spend-based)
* **DEFRA** — UK government emission factors (activity-based)
* **ecoinvent** — lifecycle assessment database (product-level)
* **IPCC AR6** — global warming potentials

Databases are updated annually. You can see which version was used in your calculation audit trail.

<Note>
  ESRS E1-6 requires reporting Scope 3 emissions in **CO2 equivalent (CO2e)**, covering all 6 GHGs from the Kyoto Protocol: CO2, CH4, N2O, HFCs, PFCs, SF6.
</Note>