Carbon consulting · UK
Carbon consultancy: what carbon consultants actually build
A carbon consultancy builds one thing that everything else depends on: a greenhouse gas inventory you can defend.
It is measured on the GHG Protocol, converted with the government’s conversion factors, and reused for SECR, ESOS, public contracts and any target or claim.
This page explains what good carbon consulting produces, where it is used, and what to ask carbon consultants before you hire.
The work
What carbon consulting produces
Carbon consultants measure an organisation’s greenhouse gas emissions, report them where a rule asks, and help reduce them over time.
The value of good carbon consulting is a single, defensible inventory, not a different number for every form.
Greenhouse gas consultants, carbon footprint consultants, carbon management consultants and emissions compliance consultants are largely names for the same work.
What differs is the use: compliance reporting, a target, a public contract, or a claim.
For targets see net zero consultancy; for the SECR disclosure itself, SECR consultancy.
A carbon consultancy’s deliverables
- An organisational boundary and the consolidation approach
- A Scope 1, 2 and 3 inventory with activity data traced to source
- A methodology note naming every factor and its year
- The figures each regime asks for, in its format
- A reduction baseline for targets and plans
Measurement
Scope 1, 2 and 3 on the GHG Protocol
| Scope | What it covers | The rule to know |
|---|---|---|
| Scope 1 | Direct emissions from owned or controlled sources — fuel combustion, company vehicles, process and fugitive emissions | Required under the Corporate Standard |
| Scope 2 | Indirect emissions from purchased electricity, heat, steam and cooling | UK SRS S2 requires the location-based figure; the market-based figure is permitted |
| Scope 3 | All other value-chain emissions, in fifteen categories — purchased goods, capital goods, travel, commuting, transport, waste, use of sold products and more | The Scope 3 Standard requires all fifteen to be accounted for, with exclusions justified |
The Corporate Standard alone treats Scope 3 as optional, and requires a minimum of Scope 1 and 2.
No Scope 3 category is “optional” under the Scope 3 Standard; UK SRS S2 asks an entity to consider all fifteen and disclose which it includes.
Scope 3 is usually the largest and hardest part, so a carbon consultant scopes it by materiality first and records the basis of every estimate.
The GHG Protocol is revising its standards, but the existing standards stay in effect until it says otherwise, with a revised standard estimated for late 2028.
UK conversion factors
Match the factor year to the activity year
UK carbon consultants convert activity data into emissions with the government’s conversion factors, published each year by DESNZ.
The 2026 set was published on 11 June 2026 and, in DESNZ’s words, is for use with activity data falling entirely or mostly within 2026.
So a company reporting its 2026 year in spring 2027 uses the 2026 factors, not the 2027 set.
The factors include SECR kWh factors, which is why the same workbook serves the directors’ report.
The 2026 electricity factors cut the data lag from two years to one.
So the change since 2025 reflects two years of grid movement, not one — do not present it as your own decarbonisation.
Where the inventory goes
One inventory, many uses
| Use | What it takes from the inventory |
|---|---|
| SECR | Energy use and the emissions from gas, transport fuel and purchased electricity (unquoted companies); a wider set for quoted companies |
| ESOS | Total energy consumption across buildings, industrial processes and transport, and the 95% that is significant |
| PPN 006 Carbon Reduction Plan | Scope 1 and 2 in full and five Scope 3 categories, for UK emissions |
| UK SRS S2 | Gross Scope 1, 2 and 3, with location-based Scope 2 — for anyone reporting voluntarily, and for listed companies in scope under the FCA’s final rules, on comply or explain from 2027 |
| Targets and claims | The baseline against which reductions are measured; credits are reported separately, never deducted |
Where ESOS applies, the assessment is reviewed by a lead assessor on an approved register, which is a different role from preparing the inventory; the ESOS consultants page explains it.
The March 2019 SECR guidance says there is no statutory requirement to have environmental information audited, though building figures that could be assured is good practice.
Standards consultants cite
ISO 14064, ISO 14068 and a scheme that no longer exists
ISO 14064-1:2018 specifies how an organisation quantifies and reports greenhouse gas emissions and removals, and is programme-neutral.
ISO 14064-3:2019 covers the verification and validation of GHG statements, work done by a verifier rather than by the consultant who prepared the inventory.
For carbon neutrality, ISO 14068-1:2023 was withdrawn on 11 September 2026 and is being replaced by ISO 14068:2026; see carbon neutral consultants.
“Carbon reduction commitment consultancy” refers to the CRC Energy Efficiency Scheme, revoked from 1 October 2018 and closed after the 2018–19 compliance year.
Choosing carbon consultants
Eight questions for a carbon consultant
- Which consolidation approach will set our boundary, and why?
- Which Scope 3 categories will you include, and how will you justify exclusions?
- Which conversion factor year for which activity data?
- Will Scope 2 be reported location-based, market-based or both?
- How will estimates be marked, and how will data gaps be closed next year?
- Which regimes will the inventory feed, and in which format?
- Do you sell offsets, software or energy products alongside the advice?
- What will we own at the end — data, model and methodology note?
Carbon Legal is an independent reference and does not carry out carbon consulting engagements itself.
A consultancy service is in development; meanwhile you can book a free 15-minute call or use the contact page, and we can introduce you to independent specialists where that helps.
Frequently asked
Questions people ask
What does a carbon consultancy do?
A carbon consultancy measures an organisation's greenhouse gas emissions, reports them in the form each regime needs, and helps reduce them. The core output is a Scope 1, 2 and 3 inventory built on the GHG Protocol and, for UK reporting, the government's conversion factors. That inventory then feeds SECR, the energy picture behind ESOS, a PPN 006 Carbon Reduction Plan, UK SRS S2 for those who report against it, and any target or claim.
What is the difference between a carbon consultant and a carbon consultancy?
A carbon consultancy is the firm; a carbon consultant is the person doing the measurement and reporting. The deliverable is the same: an auditable inventory and the disclosures that depend on it. Ask who will do the work and what they have produced before.
What are Scope 1, 2 and 3 emissions?
Under the GHG Protocol, Scope 1 is direct emissions from owned or controlled sources, Scope 2 is indirect emissions from purchased electricity, heat, steam and cooling, and Scope 3 is all other value-chain emissions across fifteen categories. The Corporate Standard alone treats Scope 3 as optional; the Scope 3 Standard requires all fifteen categories to be accounted for, with exclusions disclosed and justified.
Do carbon consultants help with SECR and ESOS?
Often, yes. The same inventory provides the energy and emissions figures for SECR in the directors' report and the energy consumption data behind an ESOS assessment. ESOS itself needs a lead assessor on an approved register to review the assessment unless an exemption applies; no credential is legally required to prepare SECR figures.
What is carbon reduction commitment consultancy?
The CRC Energy Efficiency Scheme, often called the Carbon Reduction Commitment, was revoked on 1 October 2018 and closed after the 2018–19 compliance year. SECR replaced it as the UK's energy and carbon reporting regime from 1 April 2019. A consultant offering "CRC compliance" today is describing a scheme that no longer exists.
What do ISO 14064 consultants do?
ISO 14064-1:2018 specifies how an organisation quantifies and reports its greenhouse gas emissions and removals, and ISO 14064-3:2019 specifies how a GHG statement is verified or validated. A consultant can help prepare an inventory to ISO 14064-1; verification against ISO 14064-3 is done by a separate verifier. ISO lists ISO 14064-1:2018 as to be revised, with a successor under development.
Which conversion factors should a carbon consultant use?
The set that matches the year of the activity data. DESNZ says the 2026 conversion factors are for activity data falling entirely or mostly within 2026, so a company reporting its 2026 year in 2027 uses the 2026 set, published on 11 June 2026. The 2026 set also changed the electricity method, so the change from 2025 reflects two years of grid movement.
Can carbon consultants make a carbon neutral claim credible?
They can help, but the standards have moved. PAS 2060 was withdrawn at the end of 2025, and ISO withdrew ISO 14068-1:2023 on 11 September 2026 in favour of ISO 14068:2026, which puts reductions and removals in the value chain ahead of offsetting. Offsets are never deducted from reported gross emissions.
How much does a carbon consultant cost?
This page gives no fee figures. No regulator publishes a cost schedule for carbon consultancy, and characterised market ranges are not sourced facts. Ask for a written quote against a defined boundary, scope list and reporting year.
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 and Ch 9
Scope definitions; minimum Scope 1 and 2 reporting; amended for gases (2013) and Scope 2 (2015).
- GHG ProtocolCorporate Value Chain (Scope 3) Standard (2011), Table 5.4 and §6.2
Fifteen categories; account for all and justify exclusions.
- GHG ProtocolCorporate suite standards and guidance update process
Existing standards stay in effect; revised standard estimated Q4 2028.
- DESNZGreenhouse gas reporting: conversion factors (collection)
The annual UK factor sets.
- DESNZGreenhouse gas reporting: conversion factors 2026
Published 11 June 2026; for activity data mostly within 2026.
- Department for Business and TradeUK SRS S2, ¶29(a), ¶29(a)(v) and ¶B30
Gross Scope 1, 2 and 3; location-based Scope 2 required.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers’ sustainability disclosures with international standards (30 September 2026)
The final rules: listed companies in scope report against UK SRS on a comply-or-explain basis for accounting periods starting on or after 1 January 2027.
- legislation.gov.ukSI 2018/1155 — the SECR Regulations
Energy and carbon in the directors' report from 1 April 2019.
- DESNZ / DefraEnvironmental Reporting Guidelines including SECR guidance (March 2019)
No statutory requirement for SECR data to be assured.
- GOV.UKEnergy Savings Opportunity Scheme (ESOS) — guidance
The energy assessment behind the figures, and the lead assessor registers.
- Cabinet OfficePPN 006 Technical Standard for Completion of Carbon Reduction Plans
Scope 1 and 2 in full plus five Scope 3 categories.
- ISOISO 14064-1:2018 — organisation-level GHG quantification and reporting
Stage 90.92, to be revised.
- ISOISO 14064-3:2019 — verification and validation of GHG statements
Stage 90.93, confirmed.
- ISOISO 14068-1:2023 catalogue record
Withdrawn 11 September 2026.
- ISOISO 14068 — Carbon neutrality (standard 94470)
The successor edition, dated 2026-09.
- legislation.gov.ukCRC Energy Efficiency Scheme (Revocation and Savings) Order 2018 (SI 2018/841)
The CRC scheme revoked with savings from 1 October 2018.