Begin Tackling Your Scope 3 Emissions: A Practical Guide for SMEs
When it comes to measuring and managing your carbon footprint, Scope 3 emissions can feel huge, complex, and often completely outside your immediate control.
For many SMEs, the focus naturally starts with Scope 1 and 2 emissions because they’re the ones most often requested in tenders, data requests, and day-to-day reporting. But Scope 3 emissions usually make up the vast majority of your footprint, which means ignoring them isn’t an option if you want a complete, future-proof sustainability strategy.
The good news? You don’t need to tackle all of Scope 3 at once. In this blog, we’ll break down what Scope 3 emissions are, how they’re categorised under the Greenhouse Gas (GHG) Protocol, and how you can start mapping them in manageable steps.
What are Scope 3 Emissions?
Scope 3 emissions are indirect greenhouse gas emissions that occur across your value chain, both upstream (from your suppliers) and downstream (from your customers and product use).
Here’s the quick breakdown:
Scope 1: Direct emissions from your own operations (e.g., company vehicles, onsite fuel use).
Scope 2: Indirect emissions from the energy you purchase (e.g., electricity, heating, cooling).
Scope 3: All other indirect emissions connected to your business activities but outside your direct operational control.
Think of Scope 3 as everything from the goods and services you buy, to how customers use and dispose of your products.
The 15 Categories of Scope 3 (GHG Protocol)
The Greenhouse Gas Protocol, the leading global standard for carbon accounting, defines Scope 3 clearly and sets the framework most businesses use to measure it. Under the GHG Protocol, Scope 3 emissions are split into 15 categories, covering the full spectrum of upstream and downstream activities:
Purchased goods and services
Capital goods
Fuel- and energy-related activities (not included in Scope 1 or 2)
Upstream transportation and distribution
Waste generated in operations
Business travel
Employee commuting
Upstream leased assets
Downstream transportation and distribution
Processing of sold products
Use of sold products
End-of-life treatment of sold products
Downstream leased assets
Franchises
Investments
Not every category will be relevant to your business, but understanding the framework helps you identify which ones matter most. You will be able to use these categories to tackle your Scope 3 emissions piece by piece, making it a more manageable task for your organisation.
Why SMEs Should Start Looking at Scope 3 Now
Even if Scope 1 and 2 are the immediate priority for reporting, starting your Scope 3 journey early has huge advantages:
Future-proofing: Reporting requirements are expanding, and customer or supplier requests for Scope 3 data will become more common.
Competitive edge: Being ahead of the curve builds credibility with partners, investors, and clients.
Impact potential: Scope 3 is where the biggest reduction opportunities often lie.
How to Tackle Scope 3 in Manageable Steps
Trying to measure all 15 categories in one go is overwhelming and unnecessary. Instead:
Map your business activities and identify the categories that likely have the biggest emissions impact.
Start small with one or two priority categories.
Gather data gradually, using estimates where needed and improving accuracy over time.
Document your process so you can show transparency, a core GHG Protocol principle.
This approach keeps the process achievable and builds momentum inside your organisation.
Listen for Practical Tips and Real-World Examples
We’ve dedicated the latest episode of Simplifying Sustainability to Scope 3, unpacking what it is, why it matters, and how you can approach it piece by piece.
🎧 Listen to the full episode here:
❇️ Spotify
🍎 Apple
In the conversation, Donal and Erin share practical advice for SMEs and ways to overcome common Scope 3 challenges like data gaps and supplier engagement. If you’re ready to start mapping your Scope 3 emissions without the overwhelm, this episode is your perfect next step.
Final Thought
Your Scope 3 journey doesn’t need to be perfect from the start. What matters is taking that first step and building from there.
