Emissions compliance · UK
Emissions compliance consultants: the inventory behind every disclosure
Emissions compliance consultants build the Scope 1, 2 and 3 inventory that UK disclosure rules draw on.
Each rule takes a different slice: SECR takes energy and a defined set of emissions, PPN 006 takes five Scope 3 categories, and UK SRS S2 asks for all three scopes, gross.
This page sets out what each rule needs, the conversion-factor rule, and what makes an inventory ready for assurance.
The work
What emissions compliance consultants do
Emissions compliance consultants measure an organisation’s greenhouse gas emissions and present them in the forms that UK rules require.
The core output is an inventory built on the GHG Protocol Corporate Standard, converted with the government’s conversion factors.
That one data set then feeds SECR, the energy picture behind ESOS, and UK SRS S2 for those who report against it.
Building it once, to one method, avoids the common problem of three regimes reporting three slightly different numbers for the same business.
The same work is sold as carbon footprinting or GHG consulting; the carbon consultancy page covers that wider market.
From meter to disclosure
- 01Set the boundary
Financial control, operational control or equity share — and say which.
- 02Collect activity data
Invoices, meter reads, mileage, spend — traced to source.
- 03Apply factors
The UK set matching the year of the activity data.
- 04Document
Methodology, factors, estimates and exclusions, in one note.
- 05Present per rule
SECR, PPN 006, UK SRS S2 — each in its own form.
The three scopes
Scope 1, 2 and 3, with examples
| Scope | What it covers | Typical examples |
|---|---|---|
| Scope 1 | Direct emissions from owned or controlled sources | Gas boilers, company fleet, process and refrigerant emissions |
| Scope 2 | Indirect emissions from purchased energy | Electricity, heat, steam and cooling |
| Scope 3 | All other value-chain emissions, in fifteen categories | Purchased goods and services, business travel, commuting, transport, waste, use of sold products |
The Scope 3 Standard requires all fifteen categories to be accounted for, with any exclusion disclosed and justified; no category is optional.
Where primary data is missing, which is common in Scope 3, estimates should be disclosed as estimates, with their basis stated.
By rule
What each UK rule takes from the inventory
| Rule | Scope 1 | Scope 2 | Scope 3 | Status |
|---|---|---|---|---|
| SECR (unquoted companies) | Gas combustion; fuel for transport | Purchased electricity | Not required, beyond the transport-fuel limb | In force |
| PPN 006 Carbon Reduction Plan | In full | In full | Five categories: upstream and downstream transport and distribution, waste, business travel, commuting | For in-scope bids |
| UK SRS S2 | Gross | Gross, location-based | Gross; consider all fifteen, disclose which are included | Voluntary |
| FCA PS26/19 | Comply or explain | Comply or explain | Comply or explain after a one-year relief | Final; listed companies in scope, periods from 1 Jan 2027 |
SECR also asks for energy use in kWh, at least one intensity ratio chosen by the company, the methodology and prior-year comparatives.
Offsets are never deducted: UK SRS S2 ¶29(a) asks for absolute gross emissions.
Conversion factors
Match the factor year to the activity year
The 2026 methodology paper says the 2026 factors are for activity data that falls entirely or mostly within 2026.
So a company reporting its 2026 financial year in spring 2027 uses the 2026 set, not the set published in June 2027.
For methane and nitrous oxide the 2026 factors use the IPCC’s fifth assessment report GWPs; some refrigerant values use later figures where earlier ones did not exist.
A good consultant records the factor set and year beside every figure.
The 2026 electricity factors reduced the data lag from two years to one.
The change since the 2025 set therefore reflects two years of grid movement.
Assurance readiness
Build it to be tested, even if nobody requires it
No UK entity is under a legal duty to obtain sustainability assurance.
The SECR guidance says there is no requirement in the legislation for the data to be independently assured, while recommending it as good practice.
The Financial Reporting Council issued ISSA (UK) 5000 on 12 November 2025 for voluntary use, effective for periods beginning on or after 15 December 2026, with earlier use permitted.
The FCA’s final rules in PS26/19 do not require assurance either: a listed company that obtains it names the provider, which disclosures were assured and the assurance standards used, as the consultation had proposed.
The UK ETS is the exception: an installation’s emissions report must be verified by a verifier accredited by UKAS to ISO 14065.
An assurance-ready inventory has
- A written methodology and boundary
- Activity data traced to invoices and meters
- Every factor named with its source and year
- Estimates and proxies marked as such
- Exclusions listed with reasons
Choosing emissions compliance consultants
What to ask before you hire
Ask which rules the inventory must serve, and how each will be presented from the same data.
Ask which consolidation approach sets the boundary, and which Scope 3 categories will be excluded and why.
Ask how estimates will be marked, and what will change in year two to reduce them.
Ask whether the consultant sells software, offsets or energy products, and what you will own at the end.
Carbon Legal is an independent reference and does not build inventories itself.
A service is in development; you can book a free 15-minute call or contact us, and we can introduce you to independent specialists where that helps.
Frequently asked
Questions people ask
What do emissions compliance consultants do?
Emissions compliance consultants measure a company's greenhouse gas emissions across Scope 1, 2 and 3 on the GHG Protocol, using the UK government's conversion factors, and present the inventory in the form each rule needs: SECR in the directors' report, a PPN 006 Carbon Reduction Plan, UK SRS S2 for those who report against it, and the energy data behind ESOS. The output is an inventory with a documented method and a traceable data trail.
What are Scope 1, 2 and 3 emissions?
Scope 1 is direct emissions from owned or controlled sources, such as fuel burned in boilers and company vehicles. Scope 2 is indirect emissions from purchased electricity, heat, steam and cooling. Scope 3 covers all other value-chain emissions across fifteen categories defined in the GHG Protocol Scope 3 Standard, and is usually the largest and hardest part to measure.
Which scopes does SECR require?
For large unquoted companies, SECR requires emissions from the combustion of gas, the consumption of fuel for transport and purchased electricity, with the underlying energy use in kWh, at least one intensity ratio and prior-year comparatives. Quoted companies report more widely, including emissions from any facility they operate and the UK share of their figures. SECR does not require a full Scope 3 inventory.
Does UK SRS S2 require Scope 3?
UK SRS S2 asks for gross Scope 1, 2 and 3 emissions, and for an entity to consider all fifteen Scope 3 categories and disclose which it includes. UK SRS is a voluntary standard. Under the FCA's final rules in PS26/19 (30 September 2026), listed companies in scope report against UK SRS, Scope 3 included, on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027, with a one-year Scope 3 relief during which a company only states that it is using it.
Does UK SRS S2 require dual Scope 2 reporting?
No. UK SRS S2 requires the location-based Scope 2 figure and information about contractual instruments where it is needed to understand the figure. It permits a market-based figure but does not require dual reporting, unlike the GHG Protocol Scope 2 Guidance.
What does assurance readiness mean for emissions data?
It means the inventory has a documented methodology, activity data traced to source, stated emission factors and years, and estimates marked as estimates, so an assurance provider could test it. No UK entity is required to obtain sustainability assurance today. The FRC's ISSA (UK) 5000 is for voluntary use, effective for periods beginning on or after 15 December 2026.
Is independent verification ever required?
Yes, in the UK ETS: an installation's emissions report must be verified by a verifier accredited by UKAS to ISO 14065. SECR is different; the government's guidance says there is no requirement in the legislation for the data to be independently assured.
Can offsets reduce our reported emissions?
No. UK SRS S2 paragraph 29(a) asks for absolute gross emissions, and a figure net of offsets does not meet it. Credits are reported separately as a statement about what was purchased.
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 ProtocolCorporate Accounting and Reporting Standard (2004, as amended), Ch 4 and Ch 9
Scope definitions; minimum of Scope 1 and 2.
- GHG ProtocolCorporate Value Chain (Scope 3) Standard (2011), Table 5.4 and §6.2
Fifteen categories; exclusions disclosed and justified.
- DESNZGreenhouse gas reporting: conversion factors
The UK factor sets.
- DESNZ2026 GHG Conversion Factors Methodology Paper, ¶¶1.9–1.10
For activity data entirely or mostly within 2026; AR5 GWPs for CH4 and N2O.
- Department for Business and TradeUK SRS S1 and UK SRS S2 (25 February 2026)
Published for voluntary use.
- Department for Business and TradeUK SRS S2, ¶29(a), ¶29(a)(v), ¶B30, ¶B32
Gross emissions; location-based Scope 2; consider all fifteen Scope 3 categories.
- legislation.gov.ukSI 2018/1155 — the SECR Regulations
The instrument that created SECR.
- legislation.gov.ukSI 2008/410, Schedule 7 Part 7A
¶20D: gas, transport fuel and purchased electricity for unquoted companies.
- Cabinet OfficePPN 006 Technical Standard for Completion of Carbon Reduction Plans
Scope 1 and 2 plus five Scope 3 categories; seven gases.
- FCAPS26/19: Aligning listed issuers’ sustainability disclosures with international standards (30 September 2026)
The final rules: UK SRS on comply or explain for listed companies in scope from periods starting 1 January 2027; one-year Scope 3 relief; an assurance statement only where assurance is obtained.
- FCACP26/5 ¶¶3.9, 4.8, 7.5–7.7
The consultation: proposed Scope 3 relief and comply-or-explain; proposed assurance statement.
- Financial Reporting CouncilFinancial Reporting Council
Issuer of ISSA (UK) 5000.
- Financial Reporting CouncilAssurance standards — ISSA (UK) 5000 (12 November 2025)
For voluntary use; effective 15 December 2026.
- DESNZ / DefraEnvironmental Reporting Guidelines including SECR guidance (March 2019), Ch 2 §9
No legislative requirement for independent assurance of SECR data.
- GOV.UKUK ETS for installations: how to comply
Verifier accredited by UKAS to ISO 14065.
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