Emissions · the accounting standard behind the scopes
The GHG Protocol: the standard every scope comes from
The GHG Protocol is the voluntary accounting standard that defines Scopes 1, 2 and 3; its Corporate Standard dates from March 2004, amended in 2013 and 2015.
In the UK it matters because UK SRS S2 ¶29(a)(ii) tells an entity to measure its emissions under that 2004 standard.
A consolidated revision with ISO is planned, with publication estimated for late 2028 (GHG Protocol).
The documents
Which GHG Protocol documents are in force
The GHG Protocol Corporate Accounting and Reporting Standard was published by the World Resources Institute and the World Business Council for Sustainable Development, in the revised edition of March 2004 (GHG Protocol).
It is not a single frozen document: an amendment in 2013 added nitrogen trifluoride to the six Kyoto gases, and the 2015 Scope 2 Guidance amended the treatment of purchased energy.
The Scope 3 Standard of 2011 sits beside it and is the text for value-chain emissions.
The Scope 3 Calculation Guidance of 2013 is a companion: it gives calculation methods and says to refer to the Scope 3 Standard for requirements.
The Protocol is voluntary; it binds a company only where a regime or a programme points at it.
It is not a verification standard either: it is written so that an inventory can be verified, but it does not say how verification is done (standard page).
| Document | Year | Status |
|---|---|---|
| Corporate Standard | 2004 (revised edition) | In force, as amended |
| Required gases amendment | 2013 | Adds nitrogen trifluoride |
| Scope 2 Guidance | 2015 | Amends the Corporate Standard |
| Scope 3 Standard | 2011 | In force |
| Scope 3 Calculation Guidance | 2013 | Guidance, not requirements |
How an inventory is built
Five principles and one boundary choice
The Corporate Standard builds an inventory on five principles: relevance, completeness, consistency, transparency and accuracy (Ch 1).
Completeness is the one people bend: the standard says a materiality threshold for leaving sources out is not compatible with it, because a source has to be quantified to know it is small.
The boundary is set by one of two consolidation approaches, and the standard says a company “shall” use one of them (Ch 3).
Under the equity share approach, a company counts emissions in proportion to its economic interest in each operation.
Under the control approach, it counts 100% of the emissions of operations it controls and none of those it does not, choosing either financial or operational control.
For a company that wholly owns everything it operates, the two approaches give the same boundary; joint operations are where they differ.
| Principle | What the standard asks |
|---|---|
| Relevance | An inventory that reflects the company’s emissions and serves its users’ decisions |
| Completeness | Every source within the boundary; exclusions disclosed and justified |
| Consistency | Methods that allow comparison over time; changes documented |
| Transparency | A clear audit trail; assumptions and methods disclosed |
| Accuracy | Neither systematically over nor under; uncertainty reduced as far as practicable |
The scopes
Scope 1, 2 and 3, as the standard defines them
The Protocol sorts emissions into three scopes by the company’s relationship to the source.
Scope 1 is direct: fuel burnt in the company’s boilers and vehicles, industrial process emissions, and fugitive releases such as refrigerant leaks.
Scope 2 is the emissions from generating the purchased electricity, steam, heat and cooling the company consumes.
Scope 3 is everything else in the value chain, from purchased goods to the use of sold products.
The Corporate Standard alone requires a minimum of Scope 1 and Scope 2 and calls Scope 3 an optional category (Ch 4, Ch 9).
The Scope 3 Standard goes further for a company that adopts it: it “shall account for all scope 3 emissions” and disclose and justify any exclusion, so no category is optional there.
The fifteen categories are set out on Scope 3 emissions, and what UK SRS makes of them on Scope 3 under UK SRS.
| Scope | What it covers | Under the Corporate Standard |
|---|---|---|
| Scope 1 | Direct emissions from sources the company owns or controls — combustion, processes, vehicles, fugitive releases | Required |
| Scope 2 | Indirect emissions from the generation of electricity, steam, heat and cooling the company buys and uses | Required |
| Scope 3 | All other indirect emissions in the value chain, upstream and downstream | Optional alone; required under the Scope 3 Standard |
Scope 2
Location-based, market-based, and what UK SRS asks for
The Scope 2 Guidance of 2015 introduced two methods: location-based, using average grid factors, and market-based, using the contractual instruments a company holds.
It asks for both — dual reporting — where a company has operations in markets that offer supplier-specific or contractual data.
The two totals are not gross and net: the guidance itself says they should not be read that way, because netting implies offsets.
UK SRS S2 departs from the Protocol here: it requires location-based Scope 2, and requires information about contractual instruments only where they exist and help users understand the figure (¶29(a)(v), ¶B30).
An entity can therefore comply with UK SRS S2 and publish a single, location-based Scope 2 figure.
For UK electricity, the location-based factor is the government’s conversion factor for the year of the activity.
GHG Protocol Scope 2 Guidance: both methods where contractual instruments are available.
UK SRS S2 ¶B30: location-based required; information on contractual instruments only if they exist and inform users.
UK SRS S2 ¶B31: a market-based figure is permitted, not required.
UK rules
Where UK rules point at the GHG Protocol, and where they do not
UK SRS S2 requires an entity to disclose its absolute gross greenhouse gas emissions as Scope 1, 2 and 3, measured “in accordance with the Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (2004)” (¶29(a)(i)–(ii)).
The requirement names the 2004 edition, not “the current GHG Protocol”, and carries a carve-out where a jurisdictional authority or an exchange requires a different method.
A first-year relief lets an entity keep another method it used before (¶C3), and the FCA’s final rules give listed companies the same for one year (PS26/19 ¶3.16).
Under those rules, listed companies in UKLR 6, 14, 15, 16 and 22 report against UK SRS on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027, with a one-year Scope 3 relief (PS26/19).
The consultation, CP26/5, had proposed mandatory UK SRS S2; the final rules did not adopt it.
SECR does not import the Protocol: Schedule 7 writes its own emissions duties — fuel combustion and facilities for quoted companies (¶15), gas and transport fuel for unquoted ones (¶20D) — and asks the company to state its methodology.
Scope 1 and Scope 2 are the usual shorthand for SECR’s figures, but the duty is in the Schedule’s own words; the Environmental Reporting Guidelines are guidance on preparing them.
The UK standards are explained on UK SRS S2 and GOV.UK; SECR on SECR and UK SRS.
| UK instrument | Does it require the GHG Protocol? |
|---|---|
| UK SRS S2 ¶29(a)(ii) | Yes — the 2004 Corporate Standard, unless a jurisdiction or exchange requires another method |
| FCA PS26/19 | Through UK SRS, comply or explain; one-year relief to keep an earlier method |
| SECR, SI 2008/410 Sch 7 | No — its own duties, and a methodology statement |
| DESNZ conversion factors | Use the three-scope framework, for factors only |
Gross, not net
Offsets do not reduce the inventory
The Corporate Standard measures emissions; it is not a tool for claiming reductions from projects bought as offsets.
UK SRS S2 reinforces the point with one word: it asks for “absolute gross” emissions, so a figure with offsets deducted does not meet ¶29(a) (UK SRS S2).
Where an entity sets a net target, UK SRS S2 ¶36(c) asks it to disclose the associated gross target separately.
SECR contains no netting provision, so there is no legal basis for a post-offset SECR figure either.
GHG Protocol, verbatim
“It should not be used to quantify the reductions associated with GHG mitigation projects for use as offsets or credits; the GHG Protocol for Project Accounting provides requirements and guidance for this purpose.”
Source: Corporate Standard page
What is changing
The revision: one standard, with ISO, by about 2028
GHG Protocol and ISO announced a partnership on 9 September 2025, and on 29 July 2026 the Protocol published a plan to consolidate its Corporate Standard, Scope 2 Guidance, Scope 3 Standard and a new Actions and Market Instruments workstream with ISO 14064-1 (SDP v2.0).
The result is intended to be a single, co-branded corporate standard, delivered in parts; its title is still to be settled with ISO.
The plan estimates a consolidated draft for public consultation in the second quarter of 2027 and the published standard in the fourth quarter of 2028, and says the timeline is subject to change (GHG Protocol announcement).
Those are quarter-level estimates, not dates, and guidance documents are expected only after the standard itself.
The two bodies remain independent: each keeps “full authority over their standards, reviews, and governance procedures” (partnership FAQ).
The Protocol did publish one new standard in 2026 — on land sector and removals — so it is not true that nothing has changed; what does not yet exist is a revised Corporate or Scope 3 Standard.
For UK reporters the practical point is timing: UK SRS S2 names the 2004 edition, and the FCA’s rules apply from 2027, before any revised standard is expected to exist.
- 9 Sep 2025ISO–GHG Protocol partnership announced
- Oct 2025 – Jan 2026Scope 2 consultations
Nearly 1,100 responses from 56 countries.
- 29 Jul 2026Consolidated development plan published
One co-branded corporate standard.
- Q2 2027 (est.)Consolidated draft for public consultation
- Q4 2028 (est.)Published revised standard
Guidance documents to follow later.
In practice
Building a GHG Protocol inventory for UK reporting
Boundary
Choose the consolidation approach once
Equity share or control, applied consistently across all three scopes.
Scope 2
Calculate location-based first
It is the figure UK SRS S2 requires; add market-based where instruments exist.
Factors
Match factor year to activity year
The DESNZ set for the year the energy was used, named in the methodology.
Scope 3
Screen all fifteen categories
UK SRS S2 asks you to consider every category and say which you include.
SECR
Draw the SECR subset from it
The Schedule’s own list of sources, UK-only if you are unquoted.
Record
Keep the audit trail
Transparency is a principle, and assurance, if you obtain it, starts there.
The government’s conversion factors use global warming potentials from the IPCC’s fifth assessment report for methane and nitrous oxide, consistent with UK national reporting.
DESNZ’s 2023 call for evidence on Scope 3 described Scope 3 reporting in the UK as “largely voluntary”; the FCA’s rules now bring it into listed companies’ comply-or-explain reporting.
Systems that automate these calculations are compared on the carbon management software guide, and the SECR side of the inventory is on SECR reporting thresholds.
The standards themselves are published at ghgprotocol.org.
Frequently asked
The GHG Protocol: the questions people ask
What is the GHG Protocol?
The Greenhouse Gas Protocol is a family of voluntary standards for measuring and reporting greenhouse gas emissions, published by the World Resources Institute and the World Business Council for Sustainable Development.
Its Corporate Standard, in its revised edition of March 2004, defines the organisational boundary and the three scopes that almost every corporate reporting regime uses.
What does the GHG Protocol Corporate Standard require?
It requires a company to report at least its Scope 1 and Scope 2 emissions, with Scope 3 an optional category under the Corporate Standard alone.
It sets five accounting principles — relevance, completeness, consistency, transparency and accuracy — and requires a consistent organisational boundary on either the equity share or the control approach.
What are Scope 1, 2 and 3 emissions in the GHG Protocol?
Scope 1 is direct emissions from sources the company owns or controls.
Scope 2 is indirect emissions from the generation of electricity, steam, heat and cooling the company buys and uses.
Scope 3 is every other indirect emission in the value chain, organised by the 2011 Scope 3 Standard into fifteen categories.
Is the GHG Protocol mandatory in the UK?
Not as such. It is a voluntary standard.
UK SRS S2 requires an entity applying it to measure emissions under the 2004 Corporate Standard, and listed companies report against UK SRS on a comply-or-explain basis from 2027 under the FCA’s final rules.
SECR does not require the GHG Protocol; it writes its own emissions duties and asks the company to state its methodology.
What is the difference between location-based and market-based Scope 2?
Location-based Scope 2 uses average grid emission factors for where the energy is consumed; market-based reflects the contractual instruments a company holds.
The GHG Protocol Scope 2 Guidance asks for both where contractual instruments are available.
UK SRS S2 requires the location-based figure and permits, but does not require, a market-based one.
Is the GHG Protocol being revised?
Yes.
GHG Protocol and ISO are consolidating their corporate standards into a single co-branded standard.
The plan of 29 July 2026 estimates a consolidated draft for public consultation in the second quarter of 2027 and the published revised standard in the fourth quarter of 2028.
Until then the existing standards stay in effect.
Can carbon offsets reduce GHG Protocol emissions?
No. The Corporate Standard says it should not be used to quantify reductions from mitigation projects for use as offsets or credits.
UK SRS S2 asks for absolute gross emissions, so a figure net of offsets does not meet it, and SECR has no netting provision either.
Which greenhouse gases does the GHG Protocol cover?
Seven: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride.
The 2004 text named six; nitrogen trifluoride was added by amendment in 2013.
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.
- GHG ProtocolA Corporate Accounting and Reporting Standard, revised edition (March 2004)
Ch 4: Scope 3 optional; Ch 9: a minimum of Scope 1 and Scope 2; seven gases since the 2013 amendment; updated in 2015 by the Scope 2 Guidance.
- GHG ProtocolCorporate Standard (PDF) — Ch 1 principles, Ch 3 organisational boundaries
Relevance, completeness, consistency, transparency, accuracy; equity share or control (financial or operational).
- GHG ProtocolScope 2 Guidance (2015) — an amendment to the Corporate Standard
Location-based and market-based methods; dual reporting where contractual instruments are available.
- GHG ProtocolCorporate Value Chain (Scope 3) Standard (2011)
§6.2: account for all Scope 3 and disclose and justify exclusions; Table 5.4, the fifteen categories.
- GHG ProtocolCorporate Value Chain (Scope 3) Standard — standard page
- GHG ProtocolTechnical Guidance for Calculating Scope 3 Emissions (2013)
A companion guide: calculation methods, not requirements.
- GHG ProtocolConsolidated Corporate Standard — Standard Development Plan v2.0, 29 July 2026
§9: consolidated draft for consultation est. Q2 2027; published revised standard est. Q4 2028.
- GHG ProtocolGHG Protocol announces key standard development updates, 29 July 2026
- GHG ProtocolISO–GHG Protocol partnership: frequently asked questions
The two remain fully independent in decision-making and governance.
- Department for Business and TradeUK SRS S2 — Climate-related disclosures (PDF)
¶29(a)(i)–(ii) gross emissions, measured under the 2004 Corporate Standard; ¶29(a)(v) and ¶B30 location-based Scope 2; ¶B32 Scope 3 categories; ¶C3 first-year method relief.
- Department for Business and TradeUK SRS S1 and UK SRS S2
Published 25 February 2026.
- Financial Conduct AuthorityPS26/19 — UK SRS on a comply-or-explain basis
- Financial Conduct AuthorityPS26/19 — Policy Statement (PDF)
¶3.14 one-year Scope 3 relief; ¶3.16 one-year relief to keep an earlier measurement method.
- Financial Conduct AuthorityCP26/5 — the consultation PS26/19 finalises
- legislation.gov.ukSI 2008/410 Schedule 7 — SECR
- legislation.gov.ukSI 2008/410 Schedule 7, paragraph 15 — quoted company emissions
- legislation.gov.ukSI 2008/410 Schedule 7, paragraph 20D — unquoted company emissions
- DESNZ, Defra and BEISEnvironmental Reporting Guidelines, including SECR requirements
- Department for Energy Security and Net ZeroGovernment conversion factors for company reporting
- Department for Energy Security and Net ZeroGreenhouse gas reporting: conversion factors 2026
AR5 global warming potentials for CH4 and N2O; for activity data mostly within 2026.
- Department for Energy Security and Net ZeroUK greenhouse gas emissions reporting: Scope 3 emissions — call for evidence and outcome