Which Scope 3 Categories Do SMEs Actually Need to Report?

Most small and growing businesses (SMEs) need to report only 5–7 of the 15 GHG Protocol Scope 3 categories — not all 15. The categories that matter depend on what your business does, who your suppliers are, and what your customers ask for.

This guide walks through the 15 categories, shows which typically apply to which kinds of small businesses, and explains how the rules differ between VSME (voluntary; for non-listed SMEs) and CSRD (mandatory; for in-scope large undertakings under the 2026 Omnibus thresholds). It includes a decision flow you can run through in about 15 minutes for your own business.

TL;DR

• Most SMEs report 5–7 categories out of 15, not all 15. The full list comes from the GHG Protocol Corporate Value Chain (Scope 3) Standard.
• VSME treats Scope 3 as optional in the Basic Module — disclosed under B3 only when material to the business (VSME paragraphs 50–53). Scope 1 and Scope 2 remain mandatory.
• CSRD requires Scope 3 under ESRS E1-6 if climate is material — but the 2026 Omnibus revision narrowed the in-scope population to undertakings with more than 1,000 employees and more than €450M turnover.
• The Omnibus value-chain cap prevents in-scope customers from demanding more than VSME requires from sub-1,000-employee suppliers. Most SMEs therefore report Scope 3 only voluntarily, on selected categories.
• Top 5 categories for most SMEs: Category 1 (Purchased goods and services), Category 4 (Upstream transport), Category 5 (Waste in operations), Category 6 (Business travel) and Category 7 (Employee commuting).

The 15 Scope 3 categories at a glance

Scope 3 covers all indirect emissions in your value chain — everything not in your direct (Scope 1) or purchased energy (Scope 2) footprint. The GHG Protocol Corporate Value Chain (Scope 3) Standard divides them into 15 categories grouped as upstream and downstream:

SMEs are not expected to report all 15. Both VSME and the GHG Protocol use the concept of significant categories — only those that are material to your operations need to be reported.

Per-category applicability for SMEs

The table below shows how often each category is material for a typical small business. Use it as a starting point; your own materiality assessment may flag a category as high or low based on your specific operations.

The five categories marked “high” are the most common starting set for an SME materiality assessment.

Sector starting points

If you want a sector shortcut before running a full materiality assessment, this table gives a rough starting set per business type. Treat it as a hypothesis, then validate against the materiality criteria below.

Decision flow: which categories apply to your SME?

Run through these questions in order. Each “yes” adds the category to your reporting set; each “no” excludes it (but document the reason — see the materiality section below).

1. Do you buy any goods, raw materials or services from external suppliers? → Add Category 1 (Purchased goods and services). Material for almost every SME.
2. Have you bought significant equipment, machinery, vehicles or property in the reporting year (more than 5% of turnover)? → Add Category 2 (Capital goods).
3. Do third parties transport goods to your site (inbound logistics not on your own fleet)? → Add Category 4 (Upstream transport).
4. Does your business generate measurable waste (more than typical office waste)? → Add Category 5 (Waste in operations). High for most SMEs.
5. Did staff travel by air, rail or rental vehicle for business in the reporting year? → Add Category 6 (Business travel).
6. Do you have office-based employees or a hybrid working arrangement? → Add Category 7 (Employee commuting).
7. Do you ship physical products to customers using third-party logistics? → Add Category 9 (Downstream transport).
8. Do you sell physical products that go on to be processed, used or disposed of? → Add Categories 10, 11 and/or 12 depending on which apply (processing, use phase, end-of-life).
9. Do you lease assets out to others, run franchises or hold investments in other entities? → Add Categories 13, 14 or 15 as applicable. Rare for most SMEs.

A typical SME finishes this flow with 5–7 categories.

How to decide what’s material

Materiality means significant impact or relevance. Both the GHG Protocol and VSME use the same logic: include a category if any of these apply.

• Size of the emission source — fuel use almost always material; office stationery almost never
• Influence over the activity — key suppliers and own logistics decisions count, distant downstream uses often do not
• Stakeholder expectations — large customers asking for the data, banks asking for it in lending decisions
• Financial relevance — material spend with environmental intensity (e.g. concrete, steel, transport)

A common practical heuristic: if a category is estimated to contribute less than 5% of total Scope 3 emissions and stakeholders are not asking for it, you can usually exclude it — provided you state this in your report. This is a working rule of thumb, not a regulatory threshold; the GHG Protocol does not specify a numeric materiality cut-off.

Example exclusion disclosure:

“Categories 10–15 were assessed as immaterial. The company does not manufacture products and does not operate leased assets, franchises or investments.”

Once you have selected categories, estimating the numbers is the next step. The five-step process below is standard practice for an SME.

Step 1: Choose the calculation method per category

You can mix methods across categories. The two main options are:

• Spend-based: € spent × emission factor (kg CO₂e per €)
• Activity-based: physical quantity (litres, tonnes, km) × emission factor (kg CO₂e per unit)

Activity-based is more accurate when you have the physical data; spend-based is faster when you only have invoices.

Step 2: Pull emission factors from a public source

Free public sources used widely in the EU:

• DEFRA / BEIS (UK) — published annually; widely used for transport, fuel, waste
• ADEME Base Carbone (France) — comprehensive multi-sector database
• EEA (European Environment Agency) — EU-level data
• IEA — country-level grid emission factors for electricity

For the supplier-questionnaire route, your large customer may specify which factor source to use. Match theirs if you can.

Step 3: Apply the factors to your activity data

Worked examples:

• Category 1 (spend-based): €100,000 spent on packaging × 1.8 kg CO₂e per € = 180 tCO₂e
• Category 4 (activity-based): 10,000 km of third-party transport × 0.18 kg CO₂e per km = 1.8 tCO₂e
• Category 6 (activity-based): 50,000 km of business air travel (short-haul) × 0.16 kg CO₂e per km = 8 tCO₂e

Step 4: Document your methodology

For each category, record the calculation method, the emission factor source (with date and version), and any assumptions. Auditors and customer ESG teams will look at methodology, not just the headline number.

If you lack data, see our guide on how to estimate missing data for CSRD reporting.

Step 5: Improve data quality each cycle

Year 1 estimates are typically rough. Each reporting cycle, aim to:

• Collect actual data from the largest 5–10 suppliers
• Request emission factors and intensity data in tenders and contracts
• Refine emission factors based on updated benchmarks (DEFRA and ADEME publish annually)
• Reassess which categories are material as the business evolves

By Year 3, most SMEs move from broad estimates to 70–90% primary data for the largest two or three categories. That is the level customer ESG teams typically expect for credible disclosure.

Reporting under CSRD vs VSME

The two frameworks treat Scope 3 differently.

CSRD (ESRS E1-6 — GHG emissions)

• Requires disclosure of total Scope 1, 2 and 3 emissions, with an explanation of which categories are included and which are excluded as immaterial.
• Under the 2026 Omnibus revision, CSRD now applies only to undertakings with more than 1,000 employees and more than €450M turnover. Approximately 90% of previously in-scope entities have dropped out.
• Limited assurance is required for in-scope reporters; the Omnibus rescoped the assurance timeline alongside the new wave dates.

Example CSRD disclosure:

“Scope 3 emissions (Categories 1, 4, 5, 6 and 7) were estimated using spend-based and activity-based methods and totalled 12,400 tCO₂e in FY2027. Categories 8–15 were assessed as immaterial: the company does not operate leased assets, sell physical products, run franchises or hold investments.”

VSME (B3 — Energy and GHG emissions)

• Scope 1 and Scope 2 are mandatory in the Basic Module (B3).
• Scope 3 is optional — VSME paragraphs 50–53 state that Scope 3 quantification “can be appropriate” depending on the type of activities, and that an undertaking choosing to disclose it should follow the GHG Protocol 15-category framework and report only significant categories.
• The Omnibus value-chain cap means CSRD-reporting customers cannot demand more from sub-1,000-employee suppliers than VSME requires.

Example VSME disclosure:

“The company reports Scope 1 (45 tCO₂e) and Scope 2 (210 tCO₂e) for FY2027 under VSME B3. Scope 3 has been estimated for Categories 1, 5 and 6, totalling 380 tCO₂e, using spend-based and activity-based methods with DEFRA 2026 emission factors. Other categories were assessed as not significant.”

Both approaches are valid as long as your methodology is consistent and clearly documented.

Frequently Asked Questions

Do SMEs need to report all 15 Scope 3 categories?

No. Most small businesses report 5–7 categories that are material and relevant to their operations. VSME and the GHG Protocol both use the concept of significant categories — only those that materially affect your value chain footprint need to be included. Document the reasons for excluding the rest.

Is Scope 3 mandatory under VSME?

No. VSME makes Scope 1 and Scope 2 mandatory in the Basic Module (B3). Scope 3 is optional and disclosed only when the undertaking determines it is appropriate to provide relevant information on value chain impacts (VSME paragraphs 50–53). When disclosed, it follows the GHG Protocol 15-category framework.

What happens if I exclude a category?

You must explain the reason. A short statement like “Category 14 not applicable: the company does not operate as a franchisor” is sufficient. Transparency about exclusions is more important than reporting completeness — auditors and customer ESG teams expect to see the reasoning.

Are subcontractor emissions included?

Yes. Subcontractor emissions normally fall under Category 1 (Purchased goods and services) or Category 4 (Upstream transport), depending on whether you bought a service or had goods moved. See our detailed guide on reporting subcontractor emissions.

Do I need to verify Scope 3 data with an auditor?

Under CSRD limited assurance, auditors review your methodology and consistency rather than recalculating every estimate. Keep your sources, factor versions and calculation files traceable. VSME does not legally require external assurance for non-listed SMEs.

What about the GHG Protocol Scope 3 standard revision?

The GHG Protocol launched a major revision project in 2022–2023 covering its corporate and Scope 3 standards. As of mid-2026 the existing 2011 Corporate Value Chain (Scope 3) standard remains the operative version. Watch for updates: when a revised standard is published, both VSME and CSRD-aligned reporters will move to the new methodology.

Key Terms

• Scope 3 emissions – Indirect GHG emissions from activities in your value chain, split into 15 categories by the GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard.
• Materiality – Whether a topic, impact or category is significant enough to disclose. Determined by size, influence, stakeholder expectations and financial relevance.
• Spend-based method – Estimating emissions using financial spend data multiplied by an emission factor in kg CO₂e per €.
• Activity-based method – Estimating emissions using physical quantities (litres, tonnes, km) multiplied by an emission factor in kg CO₂e per unit.
• GHG Protocol – The most widely used international framework for measuring and reporting greenhouse gas emissions; underpins both VSME and CSRD/ESRS GHG disclosures.
• VSME – Voluntary Sustainability Reporting Standard for non-listed SMEs (Basic B1–B11; Comprehensive C1–C9). Adopted as a Commission recommendation on 30 July 2025.
• ESRS E1-6 – The CSRD/ESRS disclosure requirement for GHG emissions, covering Scope 1, 2 and 3 when material.
• Omnibus I – EU directive in force from 18 March 2026 that narrowed CSRD scope and capped supplier-data demands at the VSME level for sub-1,000-employee suppliers.

Conclusion

SMEs do not need to report all 15 Scope 3 categories — only those that are material and relevant to the business. For most small businesses that means 5–7 categories: typically Categories 1, 4, 5, 6 and 7. Estimate responsibly using spend-based or activity-based methods, document your methodology clearly, and improve data quality each cycle.

This proportional approach satisfies both VSME (where Scope 3 is optional under B3) and CSRD (where it is mandatory under ESRS E1-6 for in-scope undertakings) while keeping the reporting process practical for a small business.

For an annual overview of when to collect Scope 3 data, see our annual CSRD reporting calendar.

Not sure which Scope 3 categories apply to your business? Use our interactive selector to identify which categories are most relevant to your operations:

This tool will help you determine which categories to focus on based on your business type, industry, and value chain activities.