Methodology & Standards
Carbon numbers are only as good as the standards behind them. Ours come straight from the UK Government.
DESNZ 2025 Factors
Every figure in your CarbonVerified report uses DESNZ (Department for Energy Security and Net Zero) conversion factors - the same official dataset used by FTSE companies and government suppliers. The factors are updated every June, and we automatically switch to the new set as soon as it is published.
Source: GOV.UK — Government conversion factors for company reporting
Note on 2026 Factors
The UK Government typically releases updated conversion factors in June of each year. For any data logged for 2026 prior to this release, CarbonVerified uses the 2025 factors as a temporary standard. Reports will dynamically update to 2026 standards once officially published.
GHG Protocol
The calculation follows a simple principle from the GHG Protocol Corporate Accounting and Reporting Standard - the global benchmark for business carbon accounting.
Worked Example: Electricity (Scope 2)
Here is how a real electricity figure becomes a carbon number. Say your office used 12,500 kWh of electricity last year. We look up the DESNZ 2024 UK grid factor of 0.20493 kg CO₂e per kWh and multiply:
Every category works the same way - gas, fuel, flights, waste. You enter the usage figure, we apply the right factor for your reporting year.
Audit-Grade Integrity
You can only report what actually happened. CarbonVerified won't accept future-dated or estimated consumption data - your dashboard is a record of what you actually used, not what you planned to use. That makes it audit-ready by design.
Scope 2: Location-Based vs Market-Based
There are two ways to calculate electricity emissions under the GHG Protocol. The one you use matters for PPN006.
L Location-Based
Takes the average carbon intensity of the UK national grid (the DESNZ grid factor) and applies it to your electricity usage. It reflects what actually came down the wire to your building. This is the approach required by PPN006 - and what CarbonVerified uses.
M Market-Based
Uses your energy supplier's specific emission rate instead - relevant if you're on a renewable tariff backed by REGOs. It can produce a lower Scope 2 figure, but you'll need documentation from your supplier to back it up.
Where supplier data is available, CarbonVerified can show both. For your PPN006 Carbon Reduction Plan, the location-based figure is the one that counts.
Coverage Scope
Direct Emissions
Natural Gas & Company Owned Vehicles (Fuel)
Energy Indirect
Purchased Electricity consumption (kWh)
Other Indirect
Travel, Commuting, Waste, Water & Shipping (T&D)
Scope 3 in Detail
Scope 3 is the category most often misunderstood — and the most material for the majority of SMEs. It covers every emission that occurs in your value chain but is neither a direct fuel burn nor a purchased energy bill. The categories CarbonVerified captures are those that PPN006 most commonly requires SMEs to evidence: business travel by car, rail, and domestic flights; waste sent to landfill; water consumption; and employee commuting.
These are the DESNZ-published factors that procurement auditors will expect to see evidenced when they review your Carbon Reduction Plan. Using a government-published factor for each category means your numbers are traceable to a primary source — not an estimate or a third-party model.
Although Scope 3 can theoretically extend across dozens of upstream and downstream categories — from purchased goods and services through to the end-of-life treatment of your products — the GHG Protocol explicitly allows SMEs to focus on the categories that are material to their operations. For most businesses tendering under PPN06/21, the categories above represent the vast majority of their Scope 3 footprint.
From Numbers to a Compliant Report
After you have entered your activity data, CarbonVerified produces a structured Carbon Reduction Plan PDF that follows the Crown Commercial Service template format required by PPN 06/21. The document is designed to satisfy the three components the policy mandates must be present and publicly accessible:
- Your baseline year emissions across all three scopes, broken down by activity category.
- A formal commitment to achieve net zero by 2050, consistent with government guidance.
- Documented interim reduction targets showing the trajectory from your baseline to net zero.
The report carries a methodology statement referencing DESNZ conversion factors and a verification timestamp — giving procurement teams a clear, auditable trail back to the primary government data source.
Key DESNZ 2024 Emission Factors
These are the key 2024 DESNZ factors for the activity types most SMEs need to report. We apply the exact published factor for your reporting year - no manual lookups needed. Full dataset on GOV.UK →
| Activity | Unit | kg CO₂e | Scope |
|---|---|---|---|
| UK electricity (location-based) | per kWh | 0.20493 | 2 |
| Natural gas | per kWh | 0.18254 | 1 |
| Diesel (company vehicles) | per litre | 2.51318 | 1 |
| Petrol (company vehicles) | per litre | 2.31412 | 1 |
| Average car (unknown fuel) | per km | 0.16853 | 3 |
| Domestic flight | per km (passenger) | 0.24510 | 3 |
| Water supply (UK) | per m³ | 0.34400 | 3 |
About Verification
Refers to "Self-Verification" using our software tools. The "Verified" badge indicates that you have successfully completed a data entry cycle and generated a report based on our standardised methodology. It does not imply an on-site audit by our staff.