What carbon compliance covers
Carbon compliance describes the mandatory UK obligations a company has for measuring and disclosing its energy use and greenhouse-gas emissions.
In practice that means four regimes: SECR energy and carbon reporting1, ESOS energy audits2, the climate disclosures historically made under TCFD, and the new UK Sustainability Reporting Standards3.
Underpinning all of them is a single technical foundation: an auditable emissions inventory built on the GHG Protocol Corporate Standard5.
The four UK regimes
Each regime has a distinct scope, format and deadline.
The table below summarises how they differ.
| Regime | Who it covers | Where it lands |
|---|---|---|
| SECR | Quoted companies; large unquoted companies and LLPs | Directors’ Report |
| ESOS Phase 4 | Large undertakings (250+ staff, or turnover/balance-sheet test) | Notification to Environment Agency |
| TCFD | Listed companies (legacy framework) | Annual report (transitioning) |
| UK SRS S2 | In-scope listed companies (proposed) | Annual report / sustainability disclosures |
SECR rests on SI 2018/11551, while UK SRS S2 is proposed for mandatory use under FCA CP26/5 from 1 January 20274.
How the regimes interrelate
The regimes look separate but share one foundation: a verifiable energy and emissions data set.
The same Scope 1 and Scope 2 figures that populate the SECR disclosure feed the climate metrics required by UK SRS S23, while ESOS audits the energy consumption that sits behind those numbers2.
UK SRS S2 also carries forward the four TCFD pillars — Governance, Strategy, Risk Management, and Metrics & Targets — so a company with mature TCFD reporting already holds much of the structure UK SRS expects3.
What a carbon compliance consultancy does
A carbon compliance consultancy is a specialist firm focused on meeting these obligations, rather than measurement for its own sake.
The work runs in three stages: confirm which regimes apply, build the underlying emissions data on the GHG Protocol5, then draft each disclosure in the exact format its regime demands and prepare it for assurance.
For emissions measurement specifically, our emissions compliance consultants page sets out how Scope 1, 2 and 3 data is assembled and quality-checked.
How to choose a carbon compliance consultant
Check methodology first: footprinting should follow the GHG Protocol5 and use current DESNZ conversion factors.
Confirm the consultancy can deliver the specific outputs you need — SECR disclosure1, ESOS notification2, and UK SRS S2 readiness3.
Finally, ask for an auditable methodology and data trail, so the figures can later support assurance and stand up to board and auditor scrutiny.
Frequently asked questions
What is carbon compliance in the UK?
Carbon compliance is the set of mandatory UK obligations covering energy and emissions: Streamlined Energy and Carbon Reporting (SECR) in the Directors’ Report, the Energy Savings Opportunity Scheme (ESOS) energy audits, and — for listed companies — climate disclosure that is moving from TCFD to the UK Sustainability Reporting Standards (UK SRS S2). Each regime has its own scope, format and deadline.
What does a carbon compliance consultancy do?
A carbon compliance consultancy confirms which regimes apply to you, measures the underlying energy and emissions data on the GHG Protocol using DESNZ conversion factors, drafts the disclosures in the format each regime requires, and prepares the figures for assurance. Carbon Legal is a UK carbon compliance consultancy — not a law firm — and does not give legal advice.
How do SECR, ESOS and UK SRS interrelate?
They share a common foundation: a verifiable energy and emissions inventory. The same Scope 1 and 2 data underpins SECR disclosure and feeds UK SRS S2 climate metrics, while ESOS audits the energy consumption behind those figures. Building one robust data set lets a company satisfy several regimes from a single source.
When does UK SRS climate reporting become mandatory?
UK SRS S1 and S2 were published by the Department for Business and Trade on 25 February 2026 and are currently voluntary. Under FCA consultation CP26/5, UK SRS S2 is proposed to become mandatory for in-scope listed companies for accounting periods beginning on or after 1 January 2027, with Scope 3 on a comply-or-explain basis from 1 January 2028 and UK SRS S1 from 1 January 2029, subject to the FCA Policy Statement expected in autumn 2026.
How do I choose a carbon compliance consultant?
Check that footprinting follows the GHG Protocol and current DESNZ factors, that the consultancy can deliver the specific compliance outputs you need (SECR, ESOS, UK SRS S2), and that it produces an auditable methodology and data trail so the figures can support assurance under ISSA (UK) 5000.
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