When businesses first encounter carbon reporting, Scope 1 and Scope 2 make intuitive sense — you burn gas, you use electricity. But Scope 3 stops most people in their tracks.
For many EU SMBs, Scope 3 represents 60–80% of their total carbon footprint. Yet it's the scope most businesses leave out of their first carbon report. This guide explains exactly what Scope 3 is, why it matters under CSRD, and how to calculate it without a consultant.
What Are Scope 3 Emissions?
The GHG Protocol Corporate Standarddefines Scope 3 as all indirect greenhouse gas emissions that occur in a company's value chain — both upstream (before your business) and downstream (after your business) — that are not already counted in Scope 1 or Scope 2.
In simpler terms: if it's connected to your business but you don't own or control it directly, it's Scope 3.
Scope 3 Categories for EU SMBs
The GHG Protocol defines 15 Scope 3 categories. For most EU SMBs, the relevant ones are:
Category 6 — Business Travel
Flights, train journeys, and rental cars used for business purposes. This is typically the largest Scope 3 category for service businesses.
- Short-haul return flights (<3 hours): approximately 255 kgCO₂e per return flight
- Long-haul return flights (>6 hours): approximately 1,050 kgCO₂e per return flight
- Train travel: approximately 0.041 kgCO₂e per km
Category 7 — Employee Commuting
The emissions from your employees travelling to and from work. This is often overlooked but can be significant for businesses with many office-based staff.
- Car commute: approximately 0.170 kgCO₂e per km
- Public transit: approximately 0.089 kgCO₂e per km
To calculate this, you need the average commute distance and primary transport mode for your employees. A short survey of 10–15 employees gives you a usable figure.
Category 5 — Waste Generated in Operations
The carbon impact of disposing of your office or production waste. Landfill waste produces methane as it decomposes — a potent greenhouse gas.
- General waste (landfill): approximately 0.444 kgCO₂e per kg
- Recycled waste: approximately 0.021 kgCO₂e per kg
Category 11 — Use of Sold Products (Advanced)
Relevant mainly for manufacturers — the emissions produced when customers use your product. This is optional under ESRS VSME and not required for a basic CSRD report.
Why Scope 3 Matters More Than You Think
A typical European professional services firm with 30 employees might produce:
- Scope 1 (gas heating, company car): 8 tCO₂e
- Scope 2 (office electricity): 4 tCO₂e
- Scope 3 (flights, commuting, waste): 45 tCO₂e
In this example, Scope 3 is 75% of total emissions. A report that only covers Scope 1 and 2 dramatically understates the company's true impact — and sophisticated stakeholders know it.
Is Scope 3 Mandatory Under CSRD?
Under ESRS VSME (the simplified EU standard for SMBs), Scope 3 reporting is encouraged but the level of detail required is less prescriptive than for large companies. However:
- Your large-company customers are already subject to full CSRD. Their Scope 3 includes your Scope 1 and 2. They will ask you for your emissions data as a supplier — and increasingly require Scope 3 too.
- Banks and investors are beginning to require full Scope 1, 2, and 3 data for green financing and ESG-linked loans.
- EU grant bodies increasingly score applications partly on sustainability reporting completeness.
Even if CSRD doesn't require your Scope 3 today, your customers and lenders may require it tomorrow. Starting now costs very little — waiting is an avoidable risk.
How to Calculate Scope 3 Emissions for Free
Data you need to collect
- Business travel: Pull the last 12 months of expense reports. Note flight routes (or durations) and train distances.
- Employee commuting: Send a short survey asking each employee their approximate one-way commute distance and primary mode of transport (car, bus, train, cycle).
- Waste: Request your annual waste tonnage report from your waste contractor. Ask for a split between general (landfill) and recycled waste.
- Water: Check your water bills for annual m³ consumed (optional but easy to include).
Use a Scope 3 calculator
The EmissionPlan free calculator covers all major Scope 3 categories for EU SMBs — business travel (flights by duration, train km, hotel nights), employee commuting (distance and mode), and waste (general and recycled). No sign-up required.
Enter your figures and get your Scope 3 total in tCO₂e instantly, broken down by category. You can then create a free account to save your results and generate a CSRD-ready PDF report.
Common Scope 3 Mistakes to Avoid
- Ignoring commuting entirely — for a 30-person office, commuting emissions easily exceed the total of Scope 1 and 2 combined.
- Using average flight distances — short-haul and long-haul flights have very different emission factors. A London–Frankfurt flight (2h) produces roughly 4× less CO₂e than a London–New York flight (8h).
- Forgetting hotel nights — a business traveller staying 50 nights per year in hotels produces approximately 1 tCO₂e from accommodation alone.
- Treating all waste the same — recycled waste has an emission factor 21× lower than landfill. Separating the two gives a more accurate and often more favourable result.
What Does a Good Scope 3 Report Look Like?
For a basic CSRD-ready report, your Scope 3 section should show:
- Total Scope 3 emissions in tCO₂e
- Breakdown by category (travel, commuting, waste)
- Emission factors used (e.g. DEFRA 2024)
- Data sources and estimation methodology
EmissionPlan's generated PDF includes all of these automatically, formatted for auditor review and aligned with ESRS VSME disclosure requirements.