Last updated: May 26, 2026. UK sustainability reporting is not one single rule. Companies may be dealing with Streamlined Energy and Carbon Reporting, Companies Act climate-related financial disclosures, FCA TCFD-aligned rules, FCA Sustainability Disclosure Requirements for asset managers, or the new UK Sustainability Reporting Standards. The right path depends on the entity type, listing status, size, sector, and whether the trigger is a legal requirement, investor request, lender request, or customer questionnaire.
Short answer: UK SRS S1 and UK SRS S2 were published by the UK Government on February 25, 2026 and are available for voluntary use, but UK SRS reporting is not yet mandatory for all UK companies. Current mandatory requirements still include SECR energy and carbon reporting for quoted companies and certain large unquoted companies and LLPs, mandatory climate-related financial disclosures for certain large companies and LLPs for financial years starting on or after April 6, 2022, and FCA TCFD-aligned disclosure rules for in-scope listed companies and regulated firms. The FCA has consulted on replacing its TCFD-aligned listed-company rules with UK SRS-based rules from January 1, 2027, with a policy statement expected in autumn 2026.
Who needs to report sustainability information in the UK?
The UK regime is layered. A company should start by asking which of these categories applies:
- UK quoted company or listed issuer;
- large unquoted UK company or large LLP;
- public interest entity, traded company, banking company, insurance company, or AIM company with relevant employee thresholds;
- high-turnover private company or LLP with more than 500 employees and more than £500 million turnover;
- FCA-regulated asset manager, life insurer, or pension provider;
- UK asset manager subject to the FCA's Sustainability Disclosure Requirements and investment labels regime;
- UK company with EU operations, EU listing exposure, or EU customer requirements that may bring CSRD or other non-UK reporting into the picture; or
- supplier, portfolio company, or borrower responding to a customer, investor, or lender sustainability request.
For many private companies, the legal answer may be narrower than the commercial answer. A company may not be directly required to prepare a full sustainability report, but it may still need credible GHG emissions data, policy evidence, climate-risk inputs, or supplier questionnaire responses because a customer, investor, lender, or parent company asks for them.
Streamlined Energy and Carbon Reporting
Streamlined Energy and Carbon Reporting, or SECR, is one of the UK's core mandatory energy and carbon reporting regimes. It applies for financial years beginning on or after April 1, 2019. The Government's environmental reporting guidance explains that the SECR changes require UK quoted companies to report global energy use in addition to greenhouse gas emissions in the annual directors' report. It also requires large unquoted companies and large LLPs to disclose annual energy use, GHG emissions, and related information.
In practical terms, SECR usually requires companies in scope to report:
- UK energy use, including electricity, gas, and transport fuel where applicable;
- associated greenhouse gas emissions, generally in tonnes of carbon dioxide equivalent;
- an intensity ratio chosen by the company;
- the methodology used to calculate emissions and energy use;
- energy efficiency actions taken during the reporting year; and
- comparative figures where required and available.
There is a low-energy exemption for organisations that consume 40,000 kWh or less in the reporting period, but companies relying on an exemption should still document the basis for that conclusion. SECR is often the starting point for UK GHG reporting because it forces companies to collect Scope 1 and Scope 2-style data even before they move into broader climate disclosure.
Companies Act climate-related financial disclosures
Since financial years starting on or after April 6, 2022, certain UK companies and LLPs have had to provide mandatory climate-related financial disclosures under the Companies Act and LLP regulations. These requirements are TCFD-aligned in structure and sit inside the strategic report or, for some LLPs, the energy and carbon report.
These rules are aimed at economically significant entities. They include certain publicly quoted, traded, banking, insurance, and AIM companies with more than 500 employees, as well as high-turnover companies and LLPs with more than 500 employees and more than £500 million turnover. Group and subsidiary situations need to be checked carefully because parent-level reporting can change how the obligation is satisfied.
The disclosures focus on climate-related risks and opportunities. Companies need to explain governance, strategy, risk management, and metrics and targets for climate-related matters, including the actual and potential effects of climate-related risks and opportunities on the business model and strategy where material. These disclosures should connect to the rest of the annual report rather than sit as a standalone climate paragraph.
FCA rules for listed companies and regulated firms
The FCA still has TCFD-aligned reporting requirements in force for listed companies and certain regulated firms. The current FCA page says that, taking account of the UK Listing Rules changes in July 2024, the rules apply to companies in specified listing categories, including commercial companies, international commercial companies with secondary listings, depositary receipts, non-equity shares and non-voting equity shares, and the transition category. It also covers asset managers, life insurers, and FCA-regulated pension providers.
For listed companies in scope, the annual financial report must include a statement explaining whether the company has made disclosures consistent with the TCFD recommendations and recommended disclosures. If some disclosures are elsewhere, the company needs to explain where they are. If disclosures are omitted, the company needs to explain why and describe steps and timeframes for becoming able to make the disclosures in future.
For asset managers, life insurers, and FCA-regulated pension providers, FCA rules require annual entity-level and product-level TCFD disclosures, subject to assets under management or administration thresholds. UK asset managers also need to consider the Sustainability Disclosure Requirements and investment labels regime. Under SDR, asset managers with more than £5 billion in assets under management must produce a sustainability entity report annually, with larger firms having their first report by December 2, 2025 and smaller in-scope firms by December 2, 2026.
UK Sustainability Reporting Standards
The UK Sustainability Reporting Standards, UK SRS S1 and UK SRS S2, were published by the Department for Business and Trade on February 25, 2026. They are based on the IFRS Sustainability Disclosure Standards, with UK-specific amendments. UK SRS S1 covers general sustainability-related financial disclosures, while UK SRS S2 covers climate-related disclosures and is used together with relevant parts of UK SRS S1.
As of late May 2026, UK SRS is available for voluntary use but is not yet mandatory for every UK company. The FRC's FAQ is explicit that reporting against UK SRS is not currently mandatory, while also noting that UK SRS will form the foundation of future regulation or law if and when requirements are introduced.
Two implementation tracks matter:
- Listed companies: the FCA's CP26/5 consultation proposed replacing current TCFD-aligned listing rules with UK SRS-based requirements for in-scope listed companies. The consultation closed on March 20, 2026. The FCA says it aims to publish a policy statement in autumn 2026, with rules coming into force from January 1, 2027, subject to the final UK SRS.
- Other UK companies: the Government is considering whether to introduce legal requirements to report against UK SRS through the Modernising Corporate Reporting programme. A consultation is expected in 2026, so private-company mandatory UK SRS scope is not yet settled.
The FRC has also clarified how voluntary UK SRS can interact with existing law. If a UK entity uses UK SRS S2, it does not need to duplicate Companies Act climate-related financial disclosures in its Non-Financial and Sustainability Information Statement, provided UK SRS S2 is clearly referenced and the existing Companies Act climate disclosure requirements are met. SECR is different: for now, emissions data reported under UK SRS S2 does not remove SECR reporting obligations.
What companies should prepare
Whether a company is reporting under SECR, Companies Act climate disclosure rules, FCA rules, or voluntary UK SRS, the underlying preparation work overlaps. A practical readiness plan usually includes:
- confirming which UK reporting routes apply and whether the trigger is legal, investor-led, lender-led, customer-led, or voluntary;
- mapping the reporting boundary, group structure, subsidiaries, sites, UK operations, and overseas operations;
- assigning owners across finance, legal, risk, operations, facilities, procurement, HR, sustainability, investor relations, and company secretarial teams;
- collecting energy and fuel data for SECR and Scope 1 and Scope 2 GHG emissions;
- screening Scope 3 categories, especially purchased goods and services, capital goods, logistics, business travel, employee commuting, waste, leased assets, investments, and use of sold products;
- documenting emission factors, calculation methods, boundaries, exclusions, assumptions, controls, and evidence files;
- building climate-risk and opportunity registers across physical risk and transition risk;
- connecting climate disclosures to strategy, business model, financial planning, principal risks, governance, metrics, and targets; and
- checking whether transition plan, assurance, SDR, prospectus, green bond, or customer-specific disclosure requirements also apply.
What if you are a supplier or private company?
A supplier may not be directly in scope for UK SRS, FCA listing rules, or Companies Act climate-related financial disclosures, but it may still be asked for emissions data or sustainability evidence. Large customers, listed companies, banks, private equity firms, and public-sector buyers increasingly need supplier information for Scope 3 emissions, procurement due diligence, financed emissions, risk assessment, and sustainability-labelled finance.
The first step is to interpret the actual request. A buyer may be asking for SECR-style energy and emissions numbers, a GHG inventory, a Scope 3 data submission, a CDP or EcoVadis input, policy evidence, modern slavery or human rights information, or a short customer-ready statement. Keslio's supplier request support helps turn that request into a focused response rather than a broad ESG project.
Common mistakes to avoid
- Assuming UK SRS is already mandatory for every company. UK SRS is available for voluntary use now, but mandatory application depends on FCA final rules and any future Companies Act implementation.
- Treating TCFD as obsolete in practice. TCFD itself has been disbanded, but TCFD-aligned UK rules still operate today, and the TCFD architecture is embedded in IFRS S1, IFRS S2, and UK SRS.
- Confusing SECR with full sustainability reporting. SECR is energy and carbon reporting. It does not by itself cover broader sustainability-related risks, opportunities, governance, social issues, or supply-chain impacts.
- Duplicating disclosures without checking interaction rules. UK SRS S2 may help satisfy Companies Act climate disclosure requirements if used properly, but SECR still needs to be considered separately.
- Leaving Scope 3 until the last minute. Scope 3 is harder than Scope 1 and Scope 2 because it depends on suppliers, finance, procurement, logistics, travel, products, and customer data.
How Keslio can help
Keslio helps companies turn UK sustainability reporting requirements into practical workstreams, data requests, calculations, and report content. For the UK, this can include:
- applicability checks across SECR, Companies Act climate disclosure rules, FCA rules, UK SRS readiness, SDR exposure, and supplier requests;
- GHG emissions calculations for Scope 1, Scope 2, and relevant Scope 3 categories;
- SECR data collection support, intensity ratio selection, and methodology notes;
- data request templates and evidence trackers for finance, operations, facilities, procurement, HR, logistics, and investment teams;
- TCFD or UK SRS-style gap reviews covering governance, strategy, risk management, metrics, and targets;
- methodology notes for boundaries, emission factors, exclusions, assumptions, and data limitations;
- sustainability reporting and communications for annual report content, voluntary sustainability reporting, or customer-ready disclosures; and
- supplier request support where the reporting trigger comes from a customer, lender, investor, or parent company.
This guide is not legal advice. If your company is determining formal applicability, listing-rule treatment, FCA regulatory obligations, Companies Act obligations, exemptions, or interpretation of UK law, legal counsel, auditors, company secretarial advisers, or the relevant regulator should confirm the obligation while Keslio supports the ESG data, calculations, reporting, and evidence workstream.
Sources and further reading
- UK Government publication of UK SRS S1 and UK SRS S2
- FRC sustainability reporting developments FAQ
- FCA CP26/5 on aligning listed issuer disclosures with UK SRS
- FCA sustainability reporting requirements page
- GOV.UK environmental reporting guidelines including SECR
- GOV.UK 2026 SECR regulations evaluation
- GOV.UK climate-related financial disclosures for companies and LLPs
- FRC Guidance on the Strategic Report
