Carbon compliance consultancy · United Kingdom
Carbon compliance consultancy: what UK law now requires
Carbon is now a legal quantity: carbon compliance consultancy exists because SECR, ESOS and, from 2027, UK SRS put energy and emissions into law and into the annual report.
Carbon Legal is an independent guide to that work: what each regime requires, the dates that bind you, and how to choose a carbon compliance consultant.
Exposure check
Three regimes, three different tests
SECR is an exemption test, ESOS is an either/or, and UK SRS turns on your listing category.
Every figure below is the instrument’s own.
| Regime | Who is caught | What it asks | When |
|---|---|---|---|
| SECR | Every quoted company; unquoted companies and LLPs exceeding at least two of £36m turnover, £18m balance sheet, 250 employees | Energy use, emissions, an intensity ratio, methodology and efficiency measures in the directors’ report | Every financial year, with the accounts |
| ESOS | Undertakings with at least 250 employees, or turnover over £44m and balance sheet over £38m — and their whole UK group | A four-yearly energy assessment, reviewed by a lead assessor, and a notification | Qualification 31 Dec 2026; compliance 5 Dec 2027 |
| UK SRS | Companies in five FCA listing categories; voluntary for everyone else | UK SRS S1 and S2 disclosures, on comply or explain | Accounting periods beginning on or after 1 Jan 2027 |
| Climate-related financial disclosures | Certain large companies (Companies Act s.414CA); large LLPs under their own regulations | Eight climate-related financial disclosures | Since accounting periods beginning 6 April 2022 |
The Companies Act size thresholds rose on 6 April 2025; SECR’s paragraph 20B keeps its own £36m / £18m / 250 table.
A company can be medium-sized for its accounts and still in scope for SECR.
The FCA’s final rules moved away from a mandatory UK SRS S2: listed companies disclose, or explain why not.
Scope 3 has a one-year relief; S1 non-climate matters two years.
Large companies already make climate-related financial disclosures under section 414CB of the Companies Act 2006, and the government has confirmed UK SRS S2 as a national reporting framework for that section.
To see which apply to you, use the carbon legislation readiness check.
The deadline ledger
The dates that bind you
Compliance fails on diaries, not intentions.
SECR never closes: it is due with every set of accounts.
ESOS runs in four-year phases, and the Phase 4 dates are generated by regulation 4 of the ESOS Regulations, not by guidance.
SI 2026/701 reshaped Phase 4 from 22 July 2026 — removing Display Energy Certificates and Green Deal Assessments as routes and adding a third progress update — but left the dates alone.
UK SRS reporting for listed companies, on a comply-or-explain basis, begins with accounting periods starting on or after 1 January 2027, under the FCA’s PS26/19.
Assurance is not required by any of them; ISSA (UK) 5000 is there for companies that choose it.
- Every yearSECR, with your accounts
Nine months after year end for a private company; six for a public one.
- 5 Dec 2026ESOS Phase 3 second progress update
If you filed a Phase 3 action plan.
- 15 Dec 2026ISSA (UK) 5000 effective
For voluntary assurance engagements.
- 31 Dec 2026ESOS Phase 4 qualification date
Your size on this day decides Phase 4.
- 1 Jan 2027FCA UK SRS rules apply
Accounting periods beginning on or after.
- 5 Dec 2027ESOS Phase 4 compliance date
Notify through MESOS.
- 2028First UK SRS reports
For December 2027 year ends.
- 5 Dec 2028ESOS Phase 4 action plan
The work
What carbon compliance consultants actually do
A carbon compliance consultant turns energy bills, fuel records and supplier data into figures that can stand in an annual report or a regulator’s file.
In practice that means measuring Scope 1, 2 and 3 emissions, usually with the government’s conversion factors, and keeping every figure traceable to a meter reading, invoice or supplier return.
It means drafting disclosures section by section against the paragraphs of the instrument, and running ESOS audits under a lead assessor from an approved register.
It often extends into net zero consultancy and decarbonisation planning, where the recommendations should carry their own case for and against: cost, payback, abatement and risk.
The same data set should serve every regime, which is why carbon consultancy and sustainability consultancy briefs usually cover several at once.
How to choose, regime by regime, is in the guides below; the services overview sets out the kinds of help that exist.
ESOS lead assessor sign-off needs an individual on one of seven registers the Environment Agency has approved.
Nothing else in UK carbon compliance consultancy — SECR, UK SRS, net zero — requires a statutory credential.
The guides
Start with the question you have
ESOS consultants
What ESOS consultancy involves for Phase 4, and how to check a lead assessor.
ESOS Phase 4
Qualification, the two routes, and what SI 2026/701 changed.
ESOS Phase 4 deadline
Every date to 2031, and a quarter-by-quarter plan.
SECR compliance
Scope, disclosures, deadlines and enforcement.
SECR consultancy
What a SECR engagement involves, and its cost on the government’s figures.
Choosing a SECR specialist
Ten questions, and five statements that mark a weak one.
UK SRS compliance
The FCA’s final rules, the reliefs and the 2027 timeline.
UK SRS consultancy
What UK SRS and TCFD consultants do, and how to choose one.
Carbon compliance
How the UK’s carbon regimes fit together.
Carbon consultancy
The emissions inventory behind every disclosure.
Emissions compliance
Scope 1, 2 and 3 on the GHG Protocol.
Net zero consultancy
Targets, transition plans and what they commit you to.
Decarbonisation compliance
Where decarbonisation meets a legal duty.
Sustainability consultancy
The full UK reporting stack in one programme.
Readiness check
Which UK carbon regimes apply to you.
Why this site exists
An independent guide, not a firm
Carbon Legal exists so the law never surprises you: every date on this site comes from the primary source, and every source is named.
It is published by Fractional Quest Ltd, company number 17322105, and it is not regulated, holds no credentials and has no clients.
It performs no part of anyone’s ESOS, SECR or UK SRS compliance.
It works with a network of independent specialists and can introduce you to one: book a free 15-minute call, write to hello@uksrs.org.uk, or use the contact page. More about Carbon Legal.
The wider family goes deeper: our sister reference site uksrs.org.uk covers ESOS, the ESOS Phase 4 compliance guide and SECR clause by clause.
Frequently asked
Carbon compliance — frequently asked
What does a carbon compliance consultancy do?
It helps an organisation meet the UK’s carbon and energy reporting laws: confirming which regimes apply, measuring energy use and emissions, running ESOS energy audits with a lead assessor, drafting SECR disclosures for the directors’ report, and preparing UK SRS climate reporting for listed companies. Only one of those steps — ESOS lead assessor sign-off — needs a statutory credential.
Which UK carbon regimes apply to my company?
It depends on three tests. SECR applies to every quoted company and to unquoted companies and LLPs that exceed at least two of £36 million turnover, £18 million balance sheet and 250 employees. ESOS applies to undertakings with at least 250 employees, or turnover over £44 million and balance sheet over £38 million, on 31 December 2026. UK SRS reporting applies, on comply or explain, to companies in five listing categories from 2027.
Is UK SRS mandatory from 2027?
Not in the strict sense. The FCA’s final rules in PS26/19 (30 September 2026) require listed companies in five categories to report against UK SRS S1 and S2 on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027, with first reports in 2028. UK SRS is voluntary for every other entity.
When is the ESOS Phase 4 deadline?
The ESOS Phase 4 compliance date is 5 December 2027. The qualification date, when an organisation’s size decides whether it is in, is 31 December 2026.
Is Carbon Legal a consultancy?
Carbon Legal is an independent guide to UK carbon compliance consultancy, published by Fractional Quest Ltd. It has no clients, holds no credentials and performs no part of anyone’s compliance. It works with a network of independent specialists, can introduce you to one, and offers a free 15-minute call.
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.
- legislation.gov.ukEnergy Savings Opportunity Scheme Regulations 2014 (SI 2014/1643)
ESOS.
- legislation.gov.ukSI 2014/1643, regulation 4 — ESOS compliance periods and dates
Qualification date 31 Dec 2026; compliance date 5 Dec 2027.
- legislation.gov.ukSI 2014/1643, Schedule 1 — the ESOS large-undertaking test
At least 250 employees, or turnover over £44m and balance sheet over £38m.
- legislation.gov.ukEnergy Savings Opportunity Scheme (Amendment) Regulations 2026 (SI 2026/701)
The Phase 4 changes, in force 22 July 2026.
- Environment AgencyHow to comply with the Energy Savings Opportunity Scheme (ESOS) phase 4
Published 30 July 2026.
- GOV.UKEnergy savings opportunity scheme (ESOS): find out if you qualify and how to comply
The seven approved lead assessor registers.
- legislation.gov.ukCompanies (Directors’ Report) and LLP (Energy and Carbon Report) Regulations 2018 (SI 2018/1155)
SECR, in force 1 April 2019.
- legislation.gov.ukSI 2008/410, Schedule 7, paragraph 20B — the SECR exemption test
Not more than £36m turnover, £18m balance sheet, 250 employees — two or more to be exempt.
- legislation.gov.ukCompanies Act 2006, section 414CB — climate-related financial disclosures
The climate disclosure duty for large companies in the strategic report.
- Department for Business and TradeUK Sustainability Reporting Standards: UK SRS S1 and UK SRS S2
Published 25 February 2026.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers’ sustainability disclosures with international standards
First published 30 September 2026: finalised rules requiring listed companies to report against UK SRS on a comply-or-explain basis.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers’ sustainability disclosures with international standards (PDF)
September 2026: UK SRS on comply or explain from periods beginning 1 January 2027.
- Financial Reporting CouncilISSA (UK) 5000 — General Requirements for Sustainability Assurance Engagements (PDF)
Voluntary; effective for periods beginning on or after 15 December 2026.
- Department for Energy Security and Net ZeroGovernment conversion factors for company reporting
The factors most UK energy and carbon reporting uses.