Carbon reporting requirements UK — 2026 reference guide

Three regimes currently apply to UK companies: SECR (Streamlined Energy and Carbon Reporting), mandatory since 2019 for 19,900 large quoted, large unquoted and large LLPs 1; UK SRS S2 (Climate-related Disclosures), proposed mandatory from 1 January 2027 for ~515 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. For how the four UK regimes fit together, and a checker that runs the Companies Act, SECR and ESOS scope tests on one set of your figures, see our hub on carbon reporting.

SECR applies to UK quoted companies, large unquoted companies and large LLPs. For unquoted companies, the test is SECR’s own, at Schedule 7 paragraph 20B — not the Companies Act size test: a company is exempt only if it meets two or more of turnover not more than £36 million, balance-sheet total not more than £18 million, and not more than 250 employees. LLPs are tested on the same three figures, but under a separate, modified Companies Act route (SI 2008/1911 regulation 12B) rather than Schedule 7 paragraph 20B.

Those figures did not move when the Companies Act thresholds were uplifted on 6 April 2025, so a company can be medium-sized for its accounts and still be in SECR scope. The reason is structural rather than an oversight, and the statutory architecture behind SECR sets out why the uplifting instrument could not reach paragraph 20B even though it amended the same Schedule — see the UK carbon reporting hub for the worked example.

DESNZ measured 19,900 entities in scope in its evaluation of 29 January 2026 6 — 76% more than the 11,300 the 2018 impact assessment forecast.

Quoted companies must disclose global Scope 1 and Scope 2 emissions; unquoted and LLPs disclose UK energy use plus grey-fleet Scope 3.

A 40,000 kWh de minimis relief lets very low energy users omit that disclosure, provided the report states the reason.

See SECR for the full thresholds.

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 515 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.

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, or compare carbon reporting software that builds in the current DESNZ factors and updates them each year. For the narrower question of whether a tool produces what Schedule 7 actually asks for, see SECR reporting software.

No. ESOS and SECR are 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.

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.

DESNZ (the Department for Energy Security and Net Zero) 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.

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’s interim sustainability assurance register was targeted for mid-2026 but had not opened as at the latest published record; UK practitioners may voluntarily use ISSA (UK) 5000, which is mandatory for nobody.

See sustainability assurance.