Methodology
How Carbon Recycling turns your activity data into emissions, and the choices we make on your behalf.
Standards
Calculations follow the GHG Protocol Corporate Accounting and Reporting Standard and its Scope 3 standard, and the HM Government Environmental Reporting Guidelines used for SECR. Results are in tonnes of carbon dioxide equivalent (tCO₂e), covering the seven Kyoto Protocol gases.
Conversion factors
We use the UK Government GHG Conversion Factors for Company Reporting published by the Department for Energy Security and Net Zero, loaded from the official flat files for 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026. We keep the total kg CO₂e factor for each row. All the entries in one of your reporting years use the same set: the one for the calendar year in which most of that reporting year falls (DESNZ calls this the “majority” approach), so an April to March year uses the set for the year it starts in and a July to June year uses the set for the year it ends in. Years before 2019 use the 2019 set, and years after the latest published set use the latest.
DESNZ only gave its factors stable IDs from 2023. For the 2019 to 2022 sets we match each row to the 2023 row with the same description and unit, so the same activity finds the right factor in every year. Where an older set simply doesn't include a factor (propane and butane before 2021, homeworking before 2022) we say so rather than borrowing a later year's value. Older sets don't publish well-to-tank figures for every fuel; those optional lines are left out for that year.
Every calculated line stores the factor's DESNZ ID, year and value, and is shown next to the figure in the app and in exports.
Scope 2 electricity
- Location-based: the DESNZ UK grid electricity factor.
- Market-based: zero for tariffs backed by REGOs, the supplier's fuel-mix factor when you enter one, and otherwise the grid factor.
- Transmission and distribution losses are reported separately in Scope 3 category 3.
Scope 3
Each entry is assigned to a GHG Protocol Scope 3 category. Well-to-tank emissions for the fuel and electricity you buy go to category 3. For travel and freight, where someone else buys the fuel, the well-to-tank share goes in the same category as the journey (business travel, commuting or transport), as the GHG Protocol sets out. Flights include radiative forcing by default, as DESNZ recommends. Supplier-reported figures are recorded as supplied, after you accept them.
The PPN 006 Carbon Reduction Plan reports the five categories the standard requires: upstream transport (4), waste (5), business travel (6), employee commuting (7) and downstream transport (9).
Energy for SECR
Energy in kWh is taken from bills where you enter kWh. For fuels entered by volume or mass, and for vehicles entered by distance, we derive kWh from the ratio of DESNZ factors for the same fuel, on a gross calorific value basis.
Periods
Reporting years follow your financial year. An entry covering part of a reporting year, such as a bill that crosses the year-end, is apportioned by the number of days that fall inside it.
What we don't do
- We don't net off carbon credits or offsets against your emissions.
- We don't yet estimate purchased goods from spend, because DESNZ doesn't publish spend factors. Use supplier data requests instead.
- Our figures aren't independently verified. PPN 006 doesn't require verification, but some buyers ask for it.