Scope 3 Category 1 (purchased goods and services) covers the cradle-to-gate emissions embedded in everything you buy to make your product — raw materials, components, packaging, and purchased services. For most manufacturers, it's the single largest Scope 3 category, often dwarfing every other category combined.
Key takeaways
- Category 1 covers the cradle-to-gate emissions of all purchased goods and services in a reporting year.
- It's usually the largest single Scope 3 category for manufacturers — often 40-60%+ of the total footprint.
- The GHG Protocol allows four calculation methods, from spend-based (fastest) to supplier-specific (most accurate).
- Your top 10-20 suppliers by spend usually represent the bulk of the category — start there, not with the long tail.
- EU buyers increasingly want supplier-specific data here, not spend-based estimates, for their own CSRD reporting.
What is Scope 3 Category 1?
Under the GHG Protocol's Corporate Value Chain (Scope 3) Standard, Category 1 is the first of eight upstream categories. It captures emissions that occurred before you took possession of the goods — everything from raw material extraction through to the supplier's factory gate. It excludes transport to your own facility (that's Category 4) and excludes anything after you've used the input in your own production.
See the full picture in our guide to how to calculate Scope 3 emissions across all 15 categories.
Why is Category 1 usually the largest category?
The exception: companies whose products consume significant energy in use (appliances, vehicles, machinery) often find Category 11 (use of sold products) rivals or exceeds Category 1. If you're in that position, see our companion guide on Scope 3 Category 11.
The 4 calculation methods, from fastest to most accurate
| Method | How it works | Accuracy | Effort |
|---|---|---|---|
| Spend-based | Spend (€/$) × an economic emission factor per category | Lowest | Lowest — good for a fast full baseline |
| Average-data | Quantity purchased × an industry-average emission factor | Low-medium | Low-medium |
| Hybrid | Combines spend-based and average-data depending on data availability per supplier | Medium | Medium |
| Supplier-specific | Actual verified emissions data provided directly by the supplier | Highest | Highest — needs supplier engagement |
The practical approach for most manufacturers: run a spend-based estimate across all suppliers first to see the full picture, then move your highest-spend suppliers up to hybrid or supplier-specific data. Our free carbon footprint calculator gives you a fast spend-based starting point.
How to prioritise: the 80/20 of your supplier base
- Rank suppliers by annual spend. Not by emissions yet — spend is your fastest proxy.
- Run a spend-based estimate across all of them. This gives you a rough emissions ranking too.
- Cross-reference spend rank against emissions rank. Some categories (metals, chemicals) carry far higher emission factors per euro spent than others (packaging, services).
- Engage your top 10-20 by combined spend and emissions weight. Request actual data, or explore lower-carbon material substitutions with them directly.
This is exactly the kind of supplier engagement EU buyers increasingly expect their own suppliers to demonstrate — see why CSRD makes this a commercial requirement, not just a reporting exercise.
Common mistakes with Category 1
- Using outdated or generic emission factors instead of ones matched to your specific material and region.
- Double-counting with Category 4 — make sure inbound transport is excluded from Category 1 and captured separately.
- Ignoring purchased services — Category 1 isn't just physical goods; consulting, IT, and other purchased services count too.
- Waiting for perfect data before publishing anything — a documented, defensible estimate beats silence every time.
Get your Category 1 footprint mapped properly
We identify your highest-impact suppliers, calculate Category 1 to GHG Protocol standard, and build a supplier engagement plan that satisfies EU buyer scrutiny. Backed by €2.3M PI insurance.
Explore Carbon & Net Zero Services →Frequently asked questions
What is Scope 3 Category 1?
Category 1 covers the cradle-to-gate emissions of all goods and services a company purchases in a reporting year — raw materials, components, packaging, and purchased services. For most manufacturers, it's the largest Scope 3 category.
How do you calculate Scope 3 Category 1 emissions?
The GHG Protocol allows four methods: spend-based, average-data, hybrid, and supplier-specific, in increasing order of accuracy and effort. Most companies start spend-based, then upgrade their top suppliers.
Why is Category 1 usually the largest Scope 3 category for manufacturers?
Because manufacturing inherently involves purchasing large volumes of raw materials and components carrying embedded emissions. Products that consume significant energy in use are the main exception, where Category 11 can dominate instead.
What's the fastest way to reduce Category 1 emissions?
Prioritise your top 10-20 suppliers by spend, since they usually represent the majority of the footprint. Engage them for supplier-specific data or lower-carbon alternatives before optimising smaller suppliers.
Sources & further reading
- GHG Protocol — Corporate Value Chain (Scope 3) Accounting and Reporting Standard: ghgprotocol.org/standards/scope-3-standard
- GHG Protocol — Technical Guidance for Calculating Scope 3 Emissions: ghgprotocol.org/scope-3-technical-calculation-guidance
This article is general guidance, not formal accounting advice — verify methodology against the GHG Protocol Scope 3 Standard for your inventory.