Scope 1
What the company releases: fuel it burns, vehicles and processes it owns or controls, and leaked refrigerants.
Scope 1, 2 and 3 · the GHG Protocol’s three boundaries
Scope 1, 2 and 3 emissions: where the boundary falls
Scope 1, 2 and 3 emissions are the three boxes the GHG Protocol Corporate Standard sorts a company’s greenhouse gases into: what it releases, what its purchased energy releases, and everything else in its value chain.
The box is decided by ownership and control, not by size or distance.
UK rules then ask for different boxes: SECR for roughly the first two, UK SRS S2 for all three, a Carbon Reduction Plan for the first two and five Scope 3 categories.
What decides the scope
The boundary comes first, the scope second
Before any emission can be put in a scope, the company has to decide which operations are its own.
The Corporate Standard’s Chapter 3 says companies “shall account for and report their consolidated GHG data according to either the equity share or control approach”, and a company choosing control picks operational or financial control.
For a company that wholly owns everything, the three give the same answer; for joint ventures, leases and franchises they can differ, which is why the choice has to be stated.
Once the boundary is set, the scopes follow from one question: who owns or controls the source?
Sources inside the boundary are Scope 1; the generation of energy bought into it is Scope 2; everything else the business causes upstream and downstream is Scope 3.
The split is deliberate: a company’s Scope 1 is someone else’s Scope 3, so emissions can be counted once in each inventory without being double-counted within one.
The carbon accounting reference works through boundary-setting in more detail, and the GHG Protocol page covers the standard itself.
| Approach | What you count |
|---|---|
| Equity share | Your share of each operation’s emissions, by economic interest |
| Financial control | All of the emissions of operations whose financial and operating policies you can direct |
| Operational control | All of the emissions of operations where you have full authority to introduce operating policies |
The diagram
Scope 1, 2 and 3 emissions on one diagram
The diagram beside this text is the whole idea in three boxes: the boundary comes first, and the scope says whose emissions are inside it.
Scope 1 and Scope 2 are the minimum inventory; Scope 3 is optional under the Corporate Standard alone and is asked for in full by the Scope 3 Standard.
The sections below take each scope in turn, then say which UK rule asks for which.
The carbon and emissions glossary defines the other terms, from CO2e to refrigerant emissions.
The company’s boundary
Scope 2
What generating the energy it buys releases: electricity, heat, steam and cooling.
Scope 3
Everything else in its value chain: eight upstream categories and seven downstream.
Scope 3 Standard, Table 5.4Scope 1
Scope 1: what the company releases
| Source type | What it covers | Typical UK examples |
|---|---|---|
| Stationary combustion | Fuel burned on site for heat, steam or power | Gas boilers, oil-fired heating, generators, CHP plant you control |
| Mobile combustion | Fuel burned in vehicles and plant you own or operate | Diesel vans, company cars, HGVs, forklifts, construction plant |
| Process emissions | Gases released by the process itself, not the fuel | CO2 from cement or lime, chemical reactions in manufacturing |
| Fugitive emissions | Unintended releases | Refrigerant and air-conditioning leaks, methane from gas equipment you control |
A retailer’s Scope 1 is usually gas heating in stores it controls and diesel in a fleet it runs.
A manufacturer adds process emissions from the line itself.
A software business renting serviced offices and running no vehicles can have almost none — which says nothing about its total footprint once Scope 2 and Scope 3 are added.
Fugitive refrigerant is the source most often missed, and for a business with a large cooling estate it can be a material share of Scope 1.
Under SECR, an unquoted company’s statutory minimum is narrower than all of Scope 1: ¶20D(1) names the combustion of gas and fuel for transport, so oil, process and fugitive emissions sit outside it even though the GHG Protocol counts them.
Scope 2
Scope 2: the energy you buy
Scope 2 is the emissions from generating the electricity, steam, heat and cooling a company buys and uses.
The Scope 2 Guidance counts them two ways, and asks for both where a company operates in markets with contractual instruments, such as the UK with its REGOs.
For a UK office the location-based factor is the DESNZ grid factor for the year the electricity was used: 0.13096 kgCO2e per kWh in the 2026 set.
A company that electrifies its fleet moves emissions out of Scope 1 and into Scope 2, which is why the two are best read together.
The full treatment — the methods, REGOs, the residual mix and a worked SECR layout — is on Scope 2 emissions.
Two methods, one required by UK SRS S2
Location-based: the grid average where you are.
Market-based: the factors your contracts and certificates carry.
UK SRS S2 requires location-based and permits market-based.
Sources: Scope 2 Guidance; UK SRS S2 ¶29(a)(v)
Scope 3
Scope 3: the value chain, in fifteen categories
Scope 3 is every other indirect emission the company causes, defined by the Corporate Value Chain (Scope 3) Standard in fifteen categories: eight upstream, from purchased goods to leased assets, and seven downstream, from the transport of sold products to investments.
Under the Corporate Standard alone Scope 3 is optional; a company that adopts the Scope 3 Standard “shall account for all scope 3 emissions” and disclose and justify any exclusion.
No category is optional under that standard, and a category that does not apply is reported as zero or not applicable.
For manufacturers and retailers category 1, purchased goods and services, is usually the largest; for a maker of energy-using goods it may be category 11, use of sold products; for a bank, category 15, investments.
The complete reference — every category with an example, the measurement methods and what each UK rule asks for — is Scope 3 emissions, and the listed-company view is UK SRS Scope 3 reporting.
A step-by-step inventory build is also covered by our sister site’s Scope 3 emissions reporting guide.
Classifier
Which scope is it? Pick an activity
Most classification arguments come down to who owns or controls the source, so every option on the panel says that in its own words.
The answer gives the scope and, for Scope 3, the category number the GHG Protocol uses.
It then says what SECR, a PPN 006 Carbon Reduction Plan and UK SRS S2 each do with that activity — because the same emission can be required by one and outside another.
It classifies; it does not calculate.
For the arithmetic, start from the GHG conversion factors.
Scope classifier · GHG Protocol
The answer depends on who owns or controls the source, so each option names that.
GHG Protocol Corporate Standard Ch 3–4; Scope 3 Standard Table 5.4; SI 2008/410 Sch 7 ¶¶15, 20D; PPN 006 Technical Standard; UK SRS S2 ¶¶29(a), B32.
Nothing you choose is stored or sent.
UK rules by scope
Which UK rule asks for which scope
| Instrument | Scope 1 | Scope 2 | Scope 3 | Who it reaches |
|---|---|---|---|---|
| SECR, quoted company | Fuel combustion and facilities, worldwide (¶15(2)) | Purchased electricity, heat, steam, cooling (¶15(3)) | None | Every quoted company |
| SECR, unquoted company or LLP | Gas and transport fuel, UK (¶20D(1)) | Purchased electricity (¶20D(2)) | Transport fuel it buys for business travel only | Unless it meets two or more of: turnover not more than £36m, balance sheet not more than £18m, not more than 250 employees |
| UK SRS S2, voluntary use | Gross, GHG Protocol | Gross, location-based | Gross; all 15 considered; untimed ¶C4 relief if stated | Any entity that chooses |
| UK SRS S2 under PS26/19 | Comply or explain | Comply or explain | Comply or explain after a one-year relief that must be stated | Companies listed in UKLR 6, 14, 15, 16 and 22, periods from 1 January 2027 |
| PPN 006 Carbon Reduction Plan | In full | In full | Categories 4, 5, 6, 7 and 9 | Bidders for central government contracts above £5m a year including VAT |
SECR came in through SI 2018/1155 for financial years beginning on or after 1 April 2019, and its tests depend on whether the company is quoted.
Its unquoted-company size test is an exemption written “not more than”, and it did not move when the Companies Act limits rose in April 2025; the SECR reporting guide and the carbon reporting hub work through it.
UK SRS S2 was published by the Department for Business and Trade on 25 February 2026 and is voluntary for any entity unless a rule applies it.
The FCA’s final rules (PS26/19, 30 September 2026) require companies listed in five categories to report against UK SRS on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027, replacing the proposals in CP26/5.
Under those rules nothing is mandatory: a company reports or explains why not and what it plans to do.
One method point is easy to miss: UK SRS S2 asks only for location-based Scope 2, with contractual-instrument information where it matters; the dual-reporting rule is the GHG Protocol’s.
A company already reporting under SECR reuses the same activity data and factors for UK SRS S2’s Scope 1 and 2; Scope 3 is the new build, as the UK SRS S2 and UK SRS S1 and S2 references explain.
Head to head
Scope 1 against Scope 2, line by line
| Scope 1 | Scope 2 | |
|---|---|---|
| Who releases the gas | The reporting company | A power station or heat network, for the company |
| Typical sources | Boilers, vehicles, processes, refrigerant leaks | Grid electricity, district heat, purchased steam and cooling |
| How it is calculated | Fuel or gas quantity × a DESNZ factor | kWh × the grid factor (location-based), or × contract factors (market-based) |
| Under SECR | Quoted: worldwide combustion and facilities; unquoted: UK gas and transport fuel | Quoted: electricity, heat, steam, cooling; unquoted: electricity |
| Under UK SRS S2 | Gross, split between the consolidated group and other investees (¶29(a)(iv)) | Gross, location-based, split the same way |
A short way to hold the boundary: Scope 1 is what you burn or leak, Scope 2 is what you buy as energy, and Scope 3 is what you touch without owning.
Every regime in the table above uses the same three boxes, which is what makes one inventory serve several disclosures — provided the software holds one dataset rather than one per regime, a point the carbon reporting software comparison tests.
None of the three needs third-party assurance under UK law; the sustainability assurance page explains what the FCA’s rules ask a listed company to say about it.
The measurement layer is compared in carbon accounting software.
Test yourself
Five boundary claims, true or false
Every one of these turns on the same idea: scope follows control within a chosen boundary.
The false ones put size, distance or a regime’s wording in its place.
Each answer names the provision.
Scopes: true or false?
A supplier’s factory emissions are Scope 1 for you if they are larger than your own Scope 1.
The same delivery van can be Scope 1 for one company and Scope 3 for another.
Grid transmission losses are Scope 2.
A quoted company has to report its Scope 3 under SECR.
The GHG Protocol Corporate Standard, on its own, makes Scope 3 optional.
0 of 5 answered.
Nothing you choose is stored or sent.
Frequently asked
Scope 1, 2 and 3, answered
What are Scope 1, 2 and 3 emissions?
They are the three categories the GHG Protocol Corporate Standard uses to sort a company’s greenhouse gas emissions.
Scope 1 is direct emissions from sources the company owns or controls.
Scope 2 is indirect emissions from the electricity, steam, heat and cooling it buys.
Scope 3 is every other indirect emission across its value chain, upstream and downstream.
What decides which scope an emission is in?
Ownership and control within the boundary the company has chosen — not the size of the emission or how far away it happens.
The Corporate Standard has companies consolidate either by equity share or by control, and a company choosing control picks financial or operational control.
The same van is Scope 1 if the company controls it and Scope 3 if it hires a haulier.
What is a Scope 1 emission, with an example?
A direct emission from a source the company owns or controls: gas burned in its boilers, diesel in vans it operates, CO2 released by its own industrial process, or refrigerant leaking from its air conditioning.
What is the difference between Scope 1 and Scope 2 emissions?
Scope 1 is what the company releases itself.
Scope 2 is what a power station or heat network releases to produce the energy the company buys.
Replacing gas boilers with heat pumps moves emissions from Scope 1 into Scope 2.
What is the difference between Scope 2 and Scope 3 emissions?
Scope 2 is the generation of purchased electricity, steam, heat and cooling.
Scope 3 is every other indirect emission.
The electricity lost on the grid and the upstream emissions of the fuels power stations burn are Scope 3, category 3, not Scope 2.
Does SECR require Scope 1, 2 and 3?
SECR is built around emissions that broadly match Scope 1 and 2.
Quoted companies report emissions from fuel combustion and facilities, and from purchased electricity, heat, steam and cooling, with no Scope 3 limb.
Large unquoted companies and LLPs report gas, transport fuel and purchased electricity, and the transport-fuel limb reaches fuel in personal and hire cars on business use, which is Scope 3.
Does UK SRS S2 require all three scopes?
UK SRS S2 asks for gross Scope 1, 2 and 3, measured under the GHG Protocol. It is voluntary for any entity unless a rule applies it.
Listed companies in five UK Listing Rules categories report against it on a comply-or-explain basis for periods beginning on or after 1 January 2027, with a one-year Scope 3 relief that must be stated.
Nothing in it is mandatory under those rules.
What are scope 4 emissions?
There is no Scope 4 in the GHG Protocol, whose Corporate Standard defines three scopes.
The phrase is used loosely for avoided emissions — reductions a product or financing enables elsewhere.
PCAF’s guidance, for example, says avoided emissions are reported separately and are not part of Scope 1, Scope 2 or Scope 3 accounting.
Which scope is the largest?
It depends on the business model, and Scope 3 covers far more activities than the other two: a manufacturer of energy-using goods may be dominated by use of sold products, a bank by investments, a services firm by purchased goods and travel.
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.
Checked against 16 sources fromGHG Protocollegislation.gov.ukDepartment for Business and TradeFinancial Conduct AuthorityDESNZ (GOV.UK)PCAF
- GHG ProtocolCorporate Accounting and Reporting Standard (revised edition, 2004), Chapters 3, 4 and 9
The consolidation approaches, the three scopes, and Scope 1 and 2 as the reporting minimum.
- GHG ProtocolCorporate Standard — landing page
Seven gases, NF3 added by amendment; updated in 2015 by the Scope 2 Guidance.
- GHG ProtocolScope 2 Guidance (2015)
Location-based and market-based methods.
- GHG ProtocolCorporate Value Chain (Scope 3) Standard (2011), §6.2 and Table 5.4
The fifteen categories; exclusions disclosed and justified.
- GHG ProtocolGHG Protocol — standards home
The standard-setter’s index.
- legislation.gov.ukThe Companies (Directors’ Report) and LLP (Energy and Carbon Report) Regulations 2018, SI 2018/1155
The instrument that created SECR, for financial years beginning on or after 1 April 2019.
- legislation.gov.ukSI 2008/410 Schedule 7 Parts 7 and 7A
What quoted and unquoted companies report, and the ¶20B size test.
- legislation.gov.uklegislation.gov.uk
Where every UK instrument on this page is published.
- Department for Business and TradeUK SRS S1 and UK SRS S2 (25 February 2026)
The standards, voluntary for any entity.
- Department for Business and TradeUK SRS S2, ¶¶29(a), B30, B32, C4
Gross Scope 1, 2 and 3; location-based Scope 2; all fifteen categories considered; the Scope 3 relief.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers’ sustainability disclosures with international standards
Final rules, 30 September 2026: comply or explain from periods beginning on or after 1 January 2027.
- Financial Conduct AuthorityCP26/5 — the consultation PS26/19 finalised
The proposals the final rules changed.
- Financial Conduct AuthorityFCA
The regulator that makes the listing rules.
- DESNZ (GOV.UK)UK government conversion factors for company reporting
The factors that convert activity data in each scope.
- PCAFThe Global GHG Accounting and Reporting Standard Part A, third edition (December 2025)
Avoided emissions reported separately, outside Scope 1, 2 and 3.
- Cabinet Office (GOV.UK)PPN 006 Technical Standard
Scope 1 and 2 in full and five Scope 3 categories for a Carbon Reduction Plan.