UK carbon reporting
Carbon Reporting Requirements UK (2026)
Three UK regimes currently apply: SECR (mandatory since 2019, ~11,900 entities), UK SRS S2 (proposed mandatory 1 January 2027 for ~500 listed issuers under FCA CP26/5), and ESOS (four-year audit cycle).
Companies with EU operations also face CSRD/ESRS E1.
UK carbon reporting in 2026 — at a glance
UK companies face up to four overlapping carbon reporting regimes today, depending on size, listing status and EU exposure.
SECR has been mandatory since 2019 for ~11,900 large quoted, large unquoted and large LLP entities.
UK SRS S2 is proposed mandatory for ~500 UK-listed issuers from 1 January 2027 under FCA CP26/5.
ESOS Phase 4 runs through 5 December 2027 for large UK undertakings.
UK groups with material EU subsidiaries face CSRD/ESRS E1.
The same underlying carbon inventory feeds all four — the disclosure wrappers differ.
This page is the decision-tree summary of UK carbon reporting requirements in 2026. It maps each regime to who it applies to, what is disclosed, when, and where to read the operational detail.
For deep-dives, see SECR, UK SRS S2, IFRS S2, ESOS, and the methodology backbone in carbon accounting and the GHG Protocol.
"UK SRS S2 effectively replaces TCFD-aligned listing rules. For ~500 UK-listed issuers, mandatory climate disclosure under ISSB-aligned standards begins 1 January 2027."FCA CP26/5 (January 2026)
UK carbon reporting requirements — comparison
Each UK regime applies to a specific entity profile and demands different disclosures.
The table below shows who is in scope, what they must disclose, and when each requirement applies.
| Regime | Who is in scope | What is disclosed | When |
|---|---|---|---|
| SECR (quoted companies) | UK quoted; meeting two of three: £36m turnover / £18m balance sheet / 250 employees | Global Scope 1 + 2; intensity ratio; UK + offshore energy; prior-year comparison; methodology; narrative | Annual, since 1 Apr 2019 |
| SECR (large unquoted / LLP) | UK; same thresholds | UK energy use + Scope 1 + Scope 2 + grey-fleet Scope 3 | Annual |
| UK SRS S2 | UK-listed (UKLR 6/16/22) — ~500 issuers | Scope 1 + 2 + 3 (15 categories); industry metrics; financed emissions; transition plan disclosure | Proposed mandatory 1 Jan 2027; Scope 3 c-o-e from 1 Jan 2028 |
| IFRS S2 (global) | Jurisdictional; UK adopts as UK SRS S2 | Same as UK SRS S2 | Effective 1 Jan 2024 (jurisdictional) |
| ESOS Phase 4 | Large UK undertakings: 250+ employees OR (>€50m turnover AND >€43m balance sheet) | Energy-use audit; action plan; lead-assessor sign-off | Audit period 6 Dec 2023–5 Dec 2027; qualification date 31 Dec 2026 |
| CSRD / ESRS E1 | UK groups with material EU subsidiaries above thresholds | Climate strategy, transition plan, Scope 1/2/3 under double materiality | Phased from 2024; recent EU Omnibus reduced scope |
Which UK carbon reporting requirements apply to your organisation?
Use the interactive guide below to identify which regimes apply to your organisation today and in 2027.
The decision tree covers SECR thresholds, UK SRS S2 listing-rule scope, ESOS qualification, and CSRD applicability for UK groups with EU subsidiaries.
UK carbon reporting milestone timeline
Key milestone dates from SECR's 2019 commencement through the FCA Policy Statement expected autumn 2026, UK SRS S2 mandatory 1 January 2027, Scope 3 comply-or-explain 1 January 2028, ESOS Phase 4 deadline 5 December 2027, and UK SRS S1 comply-or-explain 1 January 2029.
UK Carbon Reporting Requirements — FAQ
The most common UK carbon reporting questions, with answers linking to the dedicated regulatory pages and primary sources.
Topics: what each regime requires, who is in scope, emission factors, SECR vs ESOS, what to disclose, the SECR-to-UK SRS transition, and assurance.
What are the UK carbon reporting requirements in 2026?
Three regimes currently apply to UK companies: SECR (Streamlined Energy and Carbon Reporting), mandatory since 2019 for ~11,900 large quoted, large unquoted and large LLPs 1; UK SRS S2 (Climate-related Disclosures), proposed mandatory from 1 January 2027 for ~500 UK-listed companies under FCA CP26/5 2; and ESOS (Energy Savings Opportunity Scheme), an audit-based regime with four-year cycles.
UK companies with EU subsidiaries also face CSRD/ESRS E1 obligations — see the CSRD vs UK SRS comparison.
Who has to comply with SECR?
SECR applies to UK quoted companies, large unquoted companies and large LLPs that meet two of three Companies Act thresholds: turnover over £36 million, balance-sheet total over £18 million, or 250 or more employees. Approximately 11,900 entities are in scope.
Quoted companies must disclose global Scope 1 and Scope 2 emissions; unquoted and LLPs disclose UK energy use plus grey-fleet Scope 3. A 40 MWh de minimis exemption applies for very low energy users. See SECR for the full thresholds.
When does UK SRS S2 become mandatory?
Under FCA CP26/5 3, UK SRS S2 is proposed mandatory for in-scope listed companies (UK Listing Rules categories 6, 16 and 22 — approximately 500 issuers) from 1 January 2027, subject to the FCA Policy Statement expected autumn 2026.
Scope 3 emissions are excluded in year one and move to comply-or-explain from 1 January 2028. UK SRS S1 (non-climate sustainability) follows on comply-or-explain from 1 January 2029. See the UK SRS timeline for the full picture.
Which emission factors should I use for UK carbon reporting?
UK preparers generally use the UK Government GHG Conversion Factors for company reporting, published annually by DESNZ 4.
For Scope 3 categories outside the DESNZ dataset, the GHG Protocol Scope 3 Calculation Guidance is the operational manual. See carbon accounting for the methodology.
Does ESOS replace SECR?
No. ESOS and SECRare separate regimes that often apply to the same company. ESOS is an energy audit, performed every four years, that produces an action plan for energy savings. SECR is an annual disclosure of energy use and emissions in the Directors' Report.
Many large UK companies must comply with both, plus UK SRS S2 from 2027 if listed. See ESOS / UK SRS integration.
What does a UK company need to disclose for SECR?
Quoted companies disclose: global Scope 1 and Scope 2 emissions (gross, with intensity ratio), at least one intensity ratio, UK and offshore energy use (kWh), prior-year comparison, methodology used, and a narrative on energy-efficiency actions taken.
Unquoted companies and LLPs disclose: UK energy use plus emissions from gas, fuel-for-transport, and electricity (Scope 1, Scope 2, and grey-fleet Scope 3 only). Both must explain the methodology and any exclusions. See the SECR reporting guide for the operational detail.
Will SECR be replaced by UK SRS?
The UK Government has said it will consider the interaction between UK SRS and SECR to reduce duplication, but no replacement is confirmed. For 2026 and 2027, both regimes apply to in-scope companies.
Companies are advised to design their carbon accounting once and let the same data feed both disclosures, rather than running parallel processes. See the UK SRS compliance guide for the sequenced approach.
Is third-party assurance required for UK carbon reporting?
Not currently mandatory. SECR does not require assurance. Under UK SRS S2 / FCA CP26/5, no mandatory assurance is proposed in the initial phase — in-scope companies must disclose whether they obtained third-party assurance (disclose-or-explain), but they do not have to obtain it.
The FRC Interim Sustainability Assurance Register opens mid-2026; UK practitioners use ISSA (UK) 5000. See sustainability assurance.