The UK Sustainability Reporting Standards are UK SRS S1 (general sustainability-related disclosures) and UK SRS S2 (climate-related disclosures), published by the government on 25 February 2026. They are the UK-endorsed versions of the ISSB's IFRS S1 and IFRS S2 with a handful of amendments. On their own they are voluntary. What makes them bite is the FCA: its final rules in PS26/19 require listed companies to report against UK SRS on a comply or explain basis for accounting periods beginning on or after 1 January 2027, with first reports in 2028.
What UK SRS actually are
The ISSB, a board of the IFRS Foundation, issued IFRS S1 and IFRS S2 on 26 June 2023 to give investors a global baseline for sustainability reporting. The UK ran a consultation on exposure drafts of UK versions from 25 June to 17 September 2025, received 209 responses, and then issued the final standards. The government's own description is plain: the standards are "available for voluntary use, by any entity that chooses to do so".
Both standards share the four-part structure inherited from the old TCFD framework. UK SRS S1 paragraph 25 requires disclosures about:
- Governance. The processes, controls and procedures used to monitor and manage sustainability-related risks and opportunities;
- Strategy. The approach the entity uses to manage those risks and opportunities;
- Risk management. How risks and opportunities are identified, assessed, prioritised and monitored;
- Metrics and targets. Performance, including progress towards any targets the entity has set or is required to meet.
UK SRS S2 then applies that architecture to climate. Its cross-industry metrics cover gross Scope 1, Scope 2 and Scope 3 greenhouse gas emissions, assets or activities exposed to transition and physical risks, climate-related opportunities, capital deployment, internal carbon prices and whether climate factors feed into executive pay. It also requires climate-related scenario analysis to assess the resilience of the strategy.
How UK SRS differ from IFRS S1 and S2
The government kept the standards "as close as possible" to the ISSB baseline. The differences, mapped in Annex A of its consultation response, are narrow but practical:
- SASB and industry guidance. IFRS S1 says entities "shall refer to and consider" the SASB Standards, and IFRS S2 says the same of its industry-based guidance. The UK versions change "shall" to "may";
- No effective date. The IFRS 1 January 2024 date is removed. Entities apply UK SRS when they choose, unless law or regulation sets a date;
- No late-reporting relief. IFRS S1 let first-year reporters publish sustainability disclosures after their financial statements. The UK dropped this, so disclosures must be reported at the same time as the related financial statements and cover the same period;
- Open-ended climate-first and Scope 3 reliefs. In the ISSB text these reliefs last for the first year only. In UK SRS the time limit is removed and their availability is left to legislation or regulation;
- Compliance statements. A company that reports only on climate under the climate-first relief cannot claim compliance with UK SRS S1, but can still claim compliance with UK SRS S2 if it discloses the reliefs it has used.
Who has to use them, and from when
Listed companies. The FCA published PS26/19 on 30 September 2026. It replaces the TCFD-based listing rule with a requirement to include, in the annual financial report, either disclosures prepared under UK SRS S2 and UK SRS S1 or an explanation of what has not been disclosed, why, and the steps planned to disclose it in future. Unlike the January 2026 consultation, which proposed making most of S2 mandatory, the final rules apply comply or explain across both standards. The rules cover companies with shares listed in the commercial companies, transition, non-equity or non-voting equity shares, and secondary listing or depositary receipts categories. Optional transitional reliefs let issuers leave out the Scope 3 disclosures for one year and the wider UK SRS S1 disclosures for two years without having to explain the omission, although they must disclose which reliefs they are using.
Private companies. Nothing yet. The government has said it will consider how UK SRS should be reflected in the Companies Act 2006. Its Modernising Corporate Reporting consultation, open from 7 September to 30 November 2026, takes the question forward. In the meantime, large private companies remain under the existing climate-related financial disclosure (CFD) rules in sections 414CA and 414CB.
A worked timeline
Take a listed company with a 31 December year end that uses both reliefs. Its first period in scope is the year beginning 1 January 2027, reported in early 2028, covering S2 climate disclosures on a comply or explain basis without Scope 3. On our reading of the reliefs, Scope 3 joins for the year beginning 1 January 2028 and the wider S1 sustainability topics for the year beginning 1 January 2029. A company with a 30 June year end starts with the period beginning 1 July 2027.
The practical point is that the 2027 numbers must sit alongside the 2027 financial statements and be published at the same time. Emissions data and risk processes for 2027 need to be captured during 2027, not reconstructed in 2028.
Overlap with the Companies Act CFD rules
Some companies will be caught by both the FCA rules and the Companies Act CFD requirements. The government's position is that section 414CB(6) already lets a company meet its CFD obligations by pointing to a national or international reporting framework, and that it will confirm UK SRS counts as one. So one set of S2 disclosures should serve both regimes.
Location matters for directors' liability. The safe harbour in section 463, under which directors are liable to the company only if they knew a statement was untrue or misleading or were reckless about it, covers the strategic report and certain other reports. The government has said that, unless section 463 is expanded, only UK SRS disclosures included within the strategic report will be covered. Its September 2026 consultation adds that if sustainability disclosures were allowed outside the strategic report, it would seek to extend the section 463 protection to them.
Assurance: transparency, not compulsion
There is no requirement to have UK SRS disclosures assured. In its September 2026 consultation the government said it has no plans "at this stage" to require assurance over UK SRS reporting. The FCA rules instead require in-scope issuers to disclose any third-party assurance they obtain voluntarily: the provider, what was assured and to what level, the standards used and where the report can be found. Expect investors to read silence on that point as an answer.
Primary sources: GOV.UK: UK Sustainability Reporting Standards, the government response and Annex A mapping, FCA PS26/19, FCA sustainability reporting requirements and the Modernising Corporate Reporting consultation. For the wider regulatory picture, see our guides to ESG reporting and narrative reporting.
Acumon helps companies scope which regime applies, build an emissions and risk dataset that will stand up to scrutiny, and prepare for voluntary assurance through our ESG assurance team, with financial reporting support for integrating the disclosures into the annual report.