Explainer · Greenhouse gas scopes
Scope 1, 2 and 3 emissions, with UK examples
Scope 1, 2 and 3 emissions are the three groups every UK carbon report sorts its figures into, defined by the GHG Protocol and restated in DESNZ’s conversion factors methodology.
Scope 1 is what you burn, Scope 2 is the energy you buy, and Scope 3 is everything else in your value chain.
This page takes each scope with UK examples, the DESNZ worksheet that converts it, and the UK regime that asks for it.
The three scopes
Scope 1, 2 and 3 in DESNZ’s words
The 2026 methodology paper, ¶1.3, sorts every emissions-releasing activity into three groups.
Scope 1 (direct) emissions “are those from activities owned or controlled by your organisation”, such as combustion in owned or controlled boilers, furnaces and vehicles.
Scope 2 (energy indirect) emissions are “associated with the consumption of purchased electricity, heat, steam and cooling”, and occur at sources the organisation does not own or control.
Scope 3 (other indirect) emissions “are a consequence of your actions that occur at sources an organisation does not own or control and are not classed as Scope 2”: business travel, waste disposal, materials and fuels you buy.
DESNZ adds a warning worth keeping: whether a vehicle, office or factory you use is Scope 1 or Scope 3 “may depend on how organisations define their operational boundaries”.
The GHG Protocol Corporate Standard requires a minimum of Scope 1 and Scope 2, and treats Scope 3 as optional within that standard; the separate Scope 3 Standard requires all Scope 3, with exclusions justified.
| Scope | UK examples |
|---|---|
| Scope 1 — direct | Gas in your boilers; diesel in your vans; refrigerant leaking from your air conditioning; process emissions from your plant |
| Scope 2 — energy indirect | Grid electricity at your offices and sites; purchased heat or steam from a district network |
| Scope 3 — other indirect | Purchased goods; rail and air travel; employee commuting; waste; grid losses; the use of products you sell |
From activity to tonnes
The DESNZ worksheet that feeds each scope
The DESNZ conversion factors let users calculate “their Scope 1, 2 and 3 emissions separately”. Activity data times the matching factor gives kilograms of CO2e.
| Scope | Typical activity | DESNZ worksheet |
|---|---|---|
| Scope 1 | Natural gas, heating oil, diesel and petrol you burn | Fuels (gross CV for UK gas bills) |
| Scope 1 | Owned or leased cars and vans, by distance | Passenger vehicles; Delivery vehicles |
| Scope 1 | Refrigerant top-ups | Refrigerant & other |
| Scope 2 | Grid electricity used at your sites | UK electricity (generation): 0.13096 kgCO2e/kWh in 2026 |
| Scope 2 | Purchased heat or steam | Heat and steam |
| Scope 3, cat. 3 | Grid losses and fuel upstream | Transmission and distribution; WTT worksheets |
| Scope 3, cat. 6 | Rail, flights, hotels, grey fleet | Business travel – land / air; Hotel stay |
| Scope 3, cat. 4 or 9 | Freight you pay for | Freighting goods |
| Scope 3, cat. 5 | Waste and water treatment | Waste disposal; Water treatment |
| Scope 3, cat. 7 | Homeworking | Homeworking |
| Scope 3, cat. 1 and 2 | Purchased goods and services, capital goods, by spend | None: use Defra's spend-based multipliers |
Which year’s worksheet to use, and what changed in 2026, is on our page on the DEFRA emission factors 2026.
Spend-based estimates for purchased goods are covered in spend-based emission factors.
Scope 1
Scope 1: what you burn and release
Scope 1 is the most directly controllable part of an inventory: combustion in your own boilers, furnaces, generators and vehicles, plus process and fugitive emissions such as refrigerant leaks.
The methodology paper, ¶2.1, says fuel factors “should be used for primary fuel sources combusted at a site or in an asset owned or controlled by the reporting organisation”.
The upstream emissions of those fuels, from extraction, refining and transport, are not Scope 1: DESNZ puts well-to-tank factors in Scope 3.
Match the calorific basis of your data: UK gas suppliers generally quote kWh on a gross basis, and DESNZ says to use the gross-basis factor by default.
For SECR, a quoted company reports emissions from “the combustion of fuel” and “the operation of any facility” (Schedule 7 ¶15(2)); a large unquoted company reports the combustion of gas and the consumption of fuel for transport (¶20D(1)).
Scope 2
Scope 2: the energy you buy
Scope 2 is the emissions from generating the electricity, heat, steam and cooling you buy.
DESNZ’s electricity factor is for electricity supplied to the grid, “not including the emissions associated with the transmission and distribution of electricity”, which go to Scope 3, according to the methodology paper, ¶3.1.
The Scope 2 Guidance gives two methods: location-based, on the grid average, and market-based, on your contracts and certificates.
UK SRS S2 requires the location-based figure (¶29(a)(v)) and permits market-based (¶B31); the detail, with REGOs and the residual mix, is on our page on market-based Scope 2 emissions.
The live grid number NESO publishes is not a Scope 2 factor; our page on UK grid carbon intensity explains the difference.
Scope 3
Scope 3: the fifteen categories
The Scope 3 Standard splits the value chain into fifteen categories, eight upstream and seven downstream, and §6.2 requires companies to account for all of them and justify any exclusion.
| # | Category | Direction | UK example |
|---|---|---|---|
| 1 | Purchased goods and services | Upstream | Stock, IT services, professional fees |
| 2 | Capital goods | Upstream | Machinery, vehicles, buildings bought |
| 3 | Fuel- and energy-related activities | Upstream | Grid T&D losses; well-to-tank of fuels |
| 4 | Upstream transportation and distribution | Upstream | Inbound freight you pay for |
| 5 | Waste generated in operations | Upstream | Office and site waste, water treatment |
| 6 | Business travel | Upstream | Rail, flights, hotels, grey fleet |
| 7 | Employee commuting | Upstream | Travel to work; homeworking |
| 8 | Upstream leased assets | Upstream | Leased space outside your Scope 1 and 2 boundary |
| 9 | Downstream transportation and distribution | Downstream | Delivery of sold products you do not pay for |
| 10 | Processing of sold products | Downstream | A customer machining your components |
| 11 | Use of sold products | Downstream | Fuel burned by the boilers you sell |
| 12 | End-of-life treatment of sold products | Downstream | Disposal of your packaging |
| 13 | Downstream leased assets | Downstream | Property you own and lease out |
| 14 | Franchises | Downstream | Franchisee outlets |
| 15 | Investments | Downstream | Financed emissions of loans and equity |
No category is “optional” under the Scope 3 Standard; the word attaches to activities within a category, and a category a company does not have is reported as zero or not applicable.
UK SRS S2 is different again: ¶B32 says an entity “shall consider all 15 categories” and disclose which are included, so considering all fifteen is not the same as reporting all fifteen.
How Scope 3 works under UK SRS, including the relief, is on Scope 3 reporting under UK SRS, and the practical build is in Scope 3 emissions reporting.
Which UK regime asks for which scope
Which scopes a UK company must report
| Regime | Who | Scope 1 | Scope 2 | Scope 3 |
|---|---|---|---|---|
| SECR, quoted companies | Any quoted company | Fuel combustion and facility operation (¶15(2)) | Purchased electricity, heat, steam and cooling (¶15(3)) | Not required |
| SECR, large unquoted companies and LLPs | Exceed two of £36m / £18m / 250 (¶20B) | UK gas combustion; transport fuel (¶20D(1)) | UK purchased electricity (¶20D(2)) | Nothing beyond transport fuel for journeys (¶20D(1)(b), ¶20K) |
| UK SRS S2 | Listed companies in UKLR 6, 14, 15, 16 and 22 (FCA PS26/19) | Gross, GHG Protocol | Location-based required | Consider all 15; one year's relief; then comply or explain |
| PPN 006 carbon reduction plan | Bidders for in-scope contracts over £5m a year | In full | In full | Categories 4, 5, 6, 7 and 9 only |
SECR. A quoted company reports at any size; an unquoted company or LLP is in scope when it exceeds at least two of £36 million turnover, £18 million balance sheet total and 250 employees, under Schedule 7 ¶20B; our page on SECR thresholds works through the test.
UK SRS. The FCA’s final rules (PS26/19, 30 September 2026) require listed companies in scope to report against UK SRS on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027, with first reports in 2028.
A company may use one year’s relief from disclosing Scope 3, stating that it is doing so; after that, Scope 3 is reported or its omission explained like any other disclosure.
Carbon reduction plans. PPN 006 is procurement policy, not a duty on companies: a bidder needs a plan only where an in-scope authority applies it to a contract above £5 million a year; see our carbon reduction plan guide.
CDP. No UK instrument requires CDP disclosure; companies respond because investors or customers ask, and CDP reporting explains the process.
DESNZ’s own call for evidence summed up the position: “Scope 3 emissions remain largely voluntary” in UK reporting.
Illustrative arithmetic
A small office, worked through
Take a services business that used 250,000 kWh of grid electricity in 2026 and heats its office with gas.
Its location-based Scope 2 is 250,000 × 0.13096 kg, or 32.74 tonnes of CO2e.
The grid losses on that electricity add 3.25 tonnes, in Scope 3, category 3, not Scope 2.
Its gas bill in kWh goes through the Fuels worksheet on a gross basis to give Scope 1, and its travel through the business travel worksheets to give Scope 3, category 6.
If it applied the 2025 electricity factor, 0.17700, to the same kWh, its Scope 2 would read 44.25 tonnes: the same office, a different factor year.
| Line | Scope | Calculation | tCO2e |
|---|---|---|---|
| Grid electricity | 2 | 250,000 kWh × 0.13096 kg | 32.74 |
| Grid losses | 3, cat. 3 | 250,000 kWh × 0.01299 kg | 3.25 |
| Office gas | 1 | kWh (gross) × Fuels factor | From the workbook |
| Rail and flights | 3, cat. 6 | km × Business travel factors | From the workbook |
Where boundaries go wrong
Common scope mistakes
Grid losses reported in Scope 2: they are Scope 3, category 3.
Employees’ own cars treated as fleet: journeys in vehicles you do not own or control are business travel.
The same electric-vehicle kilowatt-hour counted twice, once in site electricity and once from the EV worksheet.
A market-based figure reported as “our Scope 2” with no location-based figure beside it, which UK SRS S2 does not accept.
Well-to-tank emissions of fuel added to Scope 1: DESNZ puts them in Scope 3.
Set the boundary first: the PPN 006 Technical Standard allows financial control, operational control or equity share, the three GHG Protocol approaches, and whichever you choose, apply it to all three scopes.
For SECR reports, SECR carbon reporting shows how the scopes map onto the directors’ report.
Frequently asked
Questions people ask
What are Scope 1, 2 and 3 emissions?
Scope 1 emissions come from activities your organisation owns or controls, such as burning gas in your boilers or diesel in your vehicles. Scope 2 emissions come from the electricity, heat, steam and cooling you buy, released where they are generated. Scope 3 is every other indirect emission in your value chain, upstream and downstream: purchased goods, business travel, waste, the use of the products you sell and more. The definitions come from the GHG Protocol and are restated in DESNZ's conversion factors methodology.
What is the difference between Scope 1 and Scope 2 emissions?
Who owns the source. Scope 1 is emissions at sources your organisation owns or controls, such as your own boilers, furnaces and vehicles. Scope 2 is emissions from generating the energy you buy, which happen at a power station or heat plant you do not own. Electricity used at your office is Scope 2; gas burned in your office boiler is Scope 1.
Which scopes must a UK company report?
It depends on the regime. Under SECR, quoted companies report emissions from fuel combustion and facility operation and from purchased electricity, heat, steam and cooling, and large unquoted companies and LLPs report UK gas, transport fuel and purchased electricity. Listed companies in scope of the FCA's final rules report against UK SRS S2, which covers Scope 1, 2 and 3, on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027. Bidders for major central government contracts may be asked for a carbon reduction plan covering Scopes 1 and 2 and five Scope 3 categories.
How many Scope 3 categories are there?
Fifteen, set by the GHG Protocol Corporate Value Chain (Scope 3) Standard: eight upstream (purchased goods and services, capital goods, fuel- and energy-related activities, upstream transportation and distribution, waste, business travel, employee commuting, upstream leased assets) and seven downstream (downstream transportation and distribution, processing of sold products, use of sold products, end-of-life treatment, downstream leased assets, franchises, investments).
Is Scope 3 mandatory in the UK?
Not as a general duty. SECR asks unquoted companies for no Scope 3 beyond transport fuel. Under the FCA's final rules, listed companies in scope report UK SRS on a comply-or-explain basis, with one year's relief from disclosing Scope 3, after which Scope 3 is reported or its omission explained. UK SRS S2 requires all 15 categories to be considered and the included categories disclosed; it does not require every category to be reported.
Are electricity transmission losses Scope 2 or Scope 3?
Scope 3. DESNZ's methodology paper says the UK electricity factor excludes transmission and distribution, and that the separate T&D factor should be used to report the Scope 3 emissions of grid losses. They belong in Scope 3, category 3, fuel- and energy-related activities.
Is a company car Scope 1 or Scope 3?
It depends on your operational boundary. Fuel burned in vehicles you own or control is Scope 1. Business journeys in vehicles you do not own or control, including employees' own cars, are Scope 3 business travel. DESNZ notes that deciding whether a vehicle, office or factory you use is Scope 1 or Scope 3 may depend on how you define your operational boundary.
What is the difference between location-based and market-based Scope 2?
Location-based Scope 2 uses the grid-average intensity where the electricity is used; for UK electricity in 2026 that is 0.13096 kgCO2e per kWh. Market-based Scope 2 uses the factors carried by your contracts and certificates, such as REGO-backed supply. UK SRS S2 requires location-based and permits market-based; the GHG Protocol asks for both where contractual instruments exist.
Sources
Primary sources
Every figure, date and status on this page traces to the instrument’s owner. Secondary commentary is never the source for a number.
- DESNZ2026 conversion factors methodology paper, ¶¶1.3, 2.1, 3.1 and Table 9
Scope 1, 2 and 3 defined in DESNZ's words; fuels, WTT and electricity allocated to scopes; the 2026 electricity factors.
- DESNZGreenhouse gas reporting: conversion factors 2026
The factors for each scope, "for their Scope 1, 2 and 3 emissions separately".
- GHG ProtocolA Corporate Accounting and Reporting Standard (revised edition, 2004)
Scopes defined; a minimum of Scope 1 and 2 required (Ch 9).
- GHG ProtocolCorporate Value Chain (Scope 3) Standard (2011), Table 5.4 and §6.2
The 15 categories; account for all and justify exclusions.
- GHG ProtocolScope 2 Guidance (2015)
Location-based and market-based Scope 2.
- Department for Business and TradeUK SRS S2 Climate-related Disclosures, ¶29(a), ¶¶B30–B33
Gross Scope 1, 2 and 3; location-based Scope 2; consider all 15 categories and disclose those included.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers' sustainability disclosures with international standards
Comply or explain from accounting periods beginning on or after 1 January 2027; one year's Scope 3 relief.
- legislation.gov.ukSI 2008/410 Schedule 7, Part 7 (quoted companies, ¶15)
Emissions from fuel combustion, facility operation and purchased electricity, heat, steam and cooling.
- legislation.gov.ukSI 2008/410 Schedule 7, Part 7A (unquoted companies, ¶20D)
UK gas, transport fuel and purchased electricity.
- legislation.gov.ukSI 2008/410 Schedule 7, ¶20B
The SECR size test for unquoted companies.
- Cabinet OfficePPN 006: Taking account of carbon reduction plans in the procurement of major government contracts
Contracts above £5 million a year, including VAT, averaged over the contract.
- Cabinet OfficePPN 006 Technical Standard for Carbon Reduction Plans
Scope 1 and 2 in full, plus five Scope 3 categories; boundary by financial control, operational control or equity share.
- DESNZUK greenhouse gas emissions reporting: Scope 3 emissions (call for evidence and outcome)
"Scope 3 emissions remain largely voluntary".