Understanding the three GHG Protocol scopes is the first step. Turning them into a greenhouse gas inventory is the next one. This Scope 1, 2 and 3 emissions example shows the data UK organisations typically collect, how that data is converted into tCO₂e, and how the figures are presented in a report.
It is an illustrative inventory for a multi-site UK organisation, not a client’s real data. Use it as a template for internal reviews, SECR working papers, carbon reduction plans and science-based target baselines. For the definitions behind each scope, see Scope 1, 2 and 3 emissions explained.
What is a Scope 1, 2 and 3 emissions inventory?
A Scope 1, 2 and 3 emissions inventory (a GHG inventory) is a 12-month account of the greenhouse gases an organisation is responsible for, broken down by scope and by source. It is the calculation layer underneath SECR, UK SRS, CDP, carbon reduction plans and SBTi targets.
Most UK inventories use:
- The GHG Protocol Corporate Standard (and the Scope 3 Standard for value-chain emissions)
- UK Government greenhouse gas conversion factors (often called the DEFRA / DESNZ factors) for the reporting year
- An organisational boundary (usually operational control)
- A fixed base year, so later years can be compared.
How to Calculate Scope 1, 2 and 3 Emissions
The underlying calculation is the same for every scope: activity data × the applicable emission factor = emissions. Where the factor is expressed in kgCO₂e per unit, divide the result by 1,000 to convert it to tCO₂e. The work is in selecting the correct activity data, conversion factor, factor year and unit of measurement.
Scope 1 – Direct emissions
Activity data: kWh of natural gas, litres of fuel in company vehicles and generators, kg of refrigerant top-ups.
Typical sources: invoices, meter reads, fuel cards, F-gas logs.
Factor: UK Government conversion factors for fuels and refrigerants.
Scope 2 – Purchased energy
Activity data: kWh of electricity, and of purchased steam, heat or cooling.
Typical sources: half-hourly data, supplier invoices, TEN / bureau reports.
Factor: location-based grid average, plus a market-based factor where a renewable contract or residual mix applies.
Scope 3 – Value chain
Activity data: spend, tonnes, passenger-km, tonne-km, or supplier-specific figures, depending on the category.
Typical sources: procurement ledgers, travel bookings, waste reports, employee commute surveys, logistics data.
Factor: UK Government Scope 3 factors, EEIO spend-based factors, or supplier-specific product carbon footprints.
Organisations should screen all 15 Scope 3 categories to identify which are relevant to their value chain. In the first reporting year, data-collection effort can be prioritised towards the most significant categories, using appropriate estimates where primary data is not yet available. Any excluded categories should be identified and the reason for their exclusion documented. Data quality can then be improved in subsequent reporting years. For what each category covers, use our Scope 3 emissions categories guide.
Related Services
Scope 1, 2 and 3 Emissions Example
The following example shows how a typical UK organisation might present a one-year inventory. Figures are rounded and illustrative.
Reporting period and boundary
Reporting period: 1 April 2025 to 31 March 2026
Organisational boundary: operational control, three UK sites plus a company car fleet
Base year: 2019/20 (aligned with TEAM’s own SBTi base year approach; organisations should pick a representative year they can hold)
Reporting period: 1 January to 31 December 2025
Factors: UK Government GHG conversion factors 2025
Activity Data
| Source | Scope | Activity data | Unit |
|---|---|---|---|
|
Natural gas (site boilers) |
Scope 1 |
1,820,400 |
kWh |
|
Company car diesel |
Scope 1 |
38,500 |
litres |
|
Refrigerant R410A top-up |
Scope 1 |
6.2 |
kg |
|
Purchased electricity |
Scope 2 |
964,250 |
kWh |
|
Electricity well-to-tank and T&D |
Scope 3 (cat. 3) |
964,250 |
kWh |
|
Natural gas well-to-tank |
Scope 3 (cat. 3) |
1,820,400 |
kWh |
|
Business travel – flights |
Scope 3 (cat. 6) |
212,000 |
passenger-km |
|
Employee commuting |
Scope 3 (cat. 7) |
1,480,000 |
passenger-km |
|
Waste – landfill and recycling |
Scope 3 (cat. 5) |
86 |
tonnes |
|
Purchased goods and services (spend-based) |
Scope 3 (cat. 1) |
4.85 |
£m |
Calculated Emissions
| Emission source | Scope | Emissions (tCO₂e) |
|---|---|---|
|
Natural gas |
Scope 1 |
333.4 |
|
Company vehicles |
Scope 1 |
97.1 |
|
Refrigerant leakage |
Scope 1 |
12.9 |
|
Purchased electricity (location-based) |
Scope 2 |
199.8 |
|
Fuel- and energy-related activities |
Scope 3 |
86.4 |
|
Business travel |
Scope 3 |
41.7 |
|
Employee commuting |
Scope 3 |
248.6 |
|
Waste generated in operations |
Scope 3 |
18.2 |
|
Purchased goods and services |
Scope 3 |
1,164.0 |
|
Total Scope 1 |
Scope 1 |
443.4 |
|
Total Scope 2 (location-based) |
Scope 2 |
199.8 |
|
Total Scope 3 (reported categories) |
Scope 3 |
1,558.9 |
|
Total inventory |
1 + 2 + 3 |
2,202.1 |
In this example Scope 3 is 71% of the inventory. That is a normal pattern, and it is why science-based targets almost always need a Scope 3 target: under current SBTi near-term criteria, Scope 3 targets are required where Scope 3 is 40% or more of total emissions.
What data you need for each scope
Location-based vs market-based Scope 2
Under the GHG Protocol Scope 2 Guidance, organisations operating in markets where contractual instruments are available should calculate and report both location-based and market-based Scope 2 emissions. Location-based reporting applies the average emissions intensity of the electricity grid serving the location. Market-based reporting reflects emissions associated with qualifying contractual instruments and supplier-specific information, with residual-mix or other prescribed data used where appropriate. For SBTi target setting and progress tracking, the organisation must disclose and consistently use its chosen Scope 2 accounting approach. UK SECR guidance prefers dual reporting but, where an organisation reports only one figure, encourages the location-based method.
Scope 2 | Electricity invoices (kWh) | Half-hourly data, supply contract (for market-based) |
Scope 3 travel and commute | Expense claims, estimated days in office | Booking-system passenger-km, staff survey |
Scope 3 purchased goods | Accounts-payable spend by category | Supplier-specific product carbon data for the top suppliers |
Scope 3 waste and water | Contractor summaries | Weighed waste by stream, metered water |
Why use a Scope 1, 2 and 3 reporting template?
- Stops sources being missed between sites
- Keeps Scope 1, Scope 2 and Scope 3 in separate columns so they can be reused for SECR, CRP and SBTi
- Makes year-on-year comparison possible
- Gives auditors a clear methodology trail
- Shows where supplier data needs to replace spend-based estimates.
Common calculation challenges
- Incomplete activity data across sites and subsidiaries
- Mixing location-based and market-based electricity in the same column
- Treating grey fleet as Scope 1 (it is Scope 3) or missing refrigerants
- Using an old conversion-factor year
- Spend-based Scope 3 that cannot be explained to an auditor or to SBTi
- No documented organisational boundary or base year
- A reliable energy and carbon data framework — meters, invoices, procurement categories and a single calculation methodology — removes most of these issues by the second reporting year.
Need Help Calculating Your Scope 1, 2 and 3 Emissions?
TEAM Energy’s carbon and data specialists build GHG inventories for SECR, carbon reduction plans, NHS/public-sector requirements and SBTi baselines. We collect the activity data, apply the correct UK conversion factors, and hand over an audit-ready Scope 1, 2 and 3 breakdown.
Greenhouse Gas Reporting Service
Scope 1, 2 and 3 emissions explained
Reducing Supply Chain Emissions
The Science Based Targets initiative (SBTi)
Call us on 01908 041930 or get in touch for a commercial greenhouse gas reporting quote.
Scope 1, 2 and 3 Calculation FAQs
Multiply activity data by the matching emission factor for each source, add the results into Scope 1, Scope 2 and Scope 3 totals, and document the methodology. The example on this page shows a typical UK layout.
Identify which of the 15 GHG Protocol categories are material, collect activity or spend data for each, apply the right factor (supplier-specific where you can, activity-based next, spend-based as a starting point), and report the total separately from Scope 1 and 2. See our Scope 3 emissions categories guide for the factor types.
Use the UK Government greenhouse gas conversion factors for the reporting year for fuels, electricity, transport, waste and water. Use supplier-specific or EEIO factors for purchased goods where Government factors do not exist. State the factor set in the methodology.
Yes. The greenhouse gas reporting service produces the Scope 1, 2 and 3 figures. Carbon reporting software keeps the calculation repeatable in later years.
Need Help Calculating Your Emissions?
Call 01908 690018 and find out how TEAM can provide accurate carbon footprinting data for mandatory Greenhouse Gas Reporting.