UK SRS S1 and S2 — The Complete Reference Guide

UK SRS S1 and S2 are the UK Sustainability Reporting Standards — the UK's endorsed versions of the ISSB's IFRS S1 and IFRS S2, published by the Department for Business and Trade on 25 February 2026.

S1 sets the general requirements for disclosing sustainability-related financial information; S2 applies that framework to climate.

Both are voluntary today, and the two standards are applied together for climate-related matters.

The paired reading of UK SRS S1 and S2 — which requirement sits in which standard — is covered in full on our primary reference site.

Under FCA CP26/5, UK SRS S2 is proposed to become mandatory for 515 listed companies in full scope for accounting periods beginning on or after 1 January 2027, with UK SRS S1 non-climate matters carrying a relief the Standard leaves untimed — the FCA proposes, not yet confirmed, that it would no longer be available for periods beginning on or after 1 January 2029.

What are UK SRS S1 and S2?

UK SRS S1: General requirements for disclosure of sustainability-related financial information.

Provides the framework and methodology for all sustainability reporting — materiality framework, "Connected information" requirement, disclosure architecture.

UK SRS S2: Climate-related disclosures applying S1's framework specifically to climate risks and opportunities, including emissions and transition plans.

Climate-specific requirements, GHG emissions disclosure, scenario analysis.

Why UK SRS S1 and S2 came together

Evolution Path:

• TCFD (2017): Task Force on Climate-related Financial Disclosures established climate reporting framework
• ISSB (2021): International Sustainability Standards Board created global baseline standards
• UK Endorsement (2026): UK adopted and amended IFRS S1 and S2 as UK SRS

The relationship is fundamental: S1 is the framework, S2 is its first application.

S1 establishes general requirements for materiality assessment, reporting boundaries, and disclosure principles that apply to all sustainability topics.

S2 then applies these principles specifically to climate-related risks and opportunities.

This two-standard approach allows entities to start with climate (using S2's climate-only relief) while building capabilities for broader sustainability reporting under S1.

Future topic-specific standards (S3, S4, etc.) will follow the same pattern, applying S1's framework to specific sustainability themes.

How UK SRS S1 and S2 are structured

Both standards follow the four-pillar architecture inherited from TCFD:

Each pillar requires disclosure of current state and forward-looking information, with quantitative metrics where possible and qualitative explanation where quantification is not yet feasible.

UK SRS S1 — the General Requirements

UK SRS S1 provides the foundational framework for all sustainability reporting:

Core requirements:

• Materiality assessment: Single materiality (financial) for UK implementation
• Reporting boundaries: Consistent with financial reporting boundaries
• Disclosure timing: Annual sustainability reporting aligned with annual reports
• "Connected information" requirement: Clear links between sustainability and financial information

Key features:

• Building blocks approach for topic-specific standards
• Proportionality for smaller entities through comply-or-explain
• Safe harbour provisions for forward-looking information
• UK-specific materiality approach (single financial materiality)

UK SRS S2 — Climate-related Disclosures

UK SRS S2 applies the S1 framework specifically to climate:

Climate-specific requirements:

• Physical risks: Assessment of acute and chronic climate risks
• Transition risks: Technology, market, policy, legal, reputation risks
• Climate opportunities: Resource efficiency, energy source, markets, resilience
• GHG emissions: Scope 1, 2, and 3 emissions with transitional reliefs

Transitional reliefs:

• Scope 3 relief: elective non-disclosure for one year; from periods beginning 1 January 2028 Scope 3 is reported on a comply-or-explain basis, drafted without a sunset
• Comparative period: first-year implementation relief
• Climate-only relief: elective non-disclosure of S1 non-climate matters, left untimed in the Standard itself — the FCA proposes, unconfirmed, that it would end for periods beginning on or after 1 January 2029

How UK SRS S1 and S2 work together

In practice:

1. Start with S2: Most entities will begin with climate disclosures under S2
2. Use S1 framework: Apply S1's materiality and disclosure principles
3. Build capability: Develop systems for broader sustainability topics
4. Expand scope: Add non-climate sustainability topics under S1 framework

Reporting sequence:

• Year 1: S2 climate disclosures, excluding Scope 3 (proposed mandatory from January 2027)
• Year 3: S1 broader sustainability, once the FCA's proposed relief cut-off is reached (periods beginning on or after January 2029, if confirmed)
• Future: Additional topic standards (S3, S4, etc.) following S1 framework

How UK SRS S1 and S2 differ from IFRS S1 and S2

The UK government consulted on six proposed amendments to IFRS S1 and S2 to address UK market conditions in June 2025, but two did not survive to publication and further provisions were added afterwards. The authoritative list of final differences is Annex A of the government's consultation response, which carries no headline count. The most significant:

1. No fixed effective date: removed from the standards; mandatory application is set by the FCA or under the Companies Act
2. Delayed reporting relief removed: sustainability disclosures must be published at the same time as the financial statements
3. Climate-first relief made untimed: the Standard removes the fixed period entirely rather than extending IFRS S1's one year — the FCA has separately proposed, unconfirmed, availability up to periods beginning before 1 January 2029
4. SASB reference softened: "may refer to and consider" rather than "shall refer to and consider"
5. Not a UK amendment: industry classification — the ISSB's own December 2025 change to IFRS S2 permits any internationally recognised classification for financed emissions, not only GICS; the UK's own proposal to drop GICS was withdrawn once the ISSB acted
6. Transitional reliefs tied to mandatory use: added paragraphs clarify how an entity states compliance when using the reliefs, with application subject to the relevant UK regulation or legislation

Who must comply, and when

Proposed scope (FCA CP26/5 proposal):

• UKLR 6 (commercial companies), UKLR 16 (non-equity shares and non-voting equity shares) and UKLR 22 (transition category) carry the UK SRS reporting obligation
• UKLR 14 (secondary listings) and UKLR 15 (depositary receipts) fall within the consultation's scope but receive a transparency and signposting statement only, not UK SRS-aligned disclosure
• 515 issuers in full scope, out of around 600 listed companies affected in total

Timeline:

• S2 (climate), excluding Scope 3: proposed mandatory from 1 January 2027
• Scope 3 emissions: elective one-year relief, then comply-or-explain from 1 January 2028, with no sunset drafted on the comply-or-explain limb
• S1 (broader sustainability): comply-or-explain, with a relief the Standard leaves untimed — the FCA proposes, unconfirmed, that it would end for periods beginning on or after 1 January 2029

Voluntary adoption: Available for any UK entity from publication date.

How UK SRS interacts with existing UK regimes

SECR (Streamlined Energy and Carbon Reporting):

• UK SRS S2 climate data can support SECR requirements
• No formal cross-referencing yet permitted
• DESNZ considering interaction to reduce duplication

TCFD disclosures:

• UK SRS S2 supersedes TCFD for in-scope entities
• Four-pillar structure maintained with enhanced requirements
• Transition period allows gradual adoption

Non-financial reporting:

• UK SRS may influence s172 strategic reports
• Enhanced links (the Standard's "Connected information" requirement) between financial and sustainability information
• Board oversight requirements aligned with corporate governance

Implementation preparation

Key preparation steps:

1. Materiality assessment: Identify climate risks and opportunities
2. Data systems: Establish GHG emissions measurement capabilities
3. Governance setup: Board and management oversight structures
4. Legal review: Understand disclosure obligations and safe harbours
5. Assurance planning: Consider independent verification requirements

For detailed implementation guidance, including compliance statement rules and common pitfalls to avoid, see the UK SRS reporting guidance.

UK SRS S1 and S2 — frequently asked questions

What are UK SRS S1 and S2?

UK SRS S1 (General Requirements for Disclosure of Sustainability-related Financial Information) and UK SRS S2 (Climate-related Disclosures) are the UK Sustainability Reporting Standards, published by the Department for Business and Trade on 25 February 2026 and available for voluntary use immediately.

They are the UK's endorsed versions of the ISSB's IFRS S1 and IFRS S2, with UK-specific differences from the global baseline, set out in Annex A of the government's consultation response.

What is the difference between UK SRS S1 and UK SRS S2?

UK SRS S1 sets the general requirements for disclosing sustainability-related financial information — materiality, reporting boundary and the "Connected information" requirement with the financial statements — and applies to every material sustainability topic.

UK SRS S2 applies that framework to climate specifically, covering climate-related risks and opportunities, greenhouse gas emissions, scenario analysis and transition plan disclosure.

S1 is the framework; S2 is its first application, and the two are applied together for climate-related matters.

When do UK SRS S1 and S2 apply?

Both have been available for voluntary use since 25 February 2026.

Under FCA CP26/5, UK SRS S2 climate disclosures excluding Scope 3 are proposed to become mandatory for 515 listed companies in full scope for accounting periods beginning on or after 1 January 2027.

Scope 3 carries an elective one-year relief and then falls to comply-or-explain from periods beginning 1 January 2028.

UK SRS S1 non-climate matters are comply-or-explain; the Standard's own relief carries no fixed period, but the FCA proposes, not yet confirmed, that it would no longer be available for periods beginning on or after 1 January 2029.

Are UK SRS S1 and S2 mandatory?

No.

UK SRS is voluntary for all entities today, and no UK entity is currently required by law to report against UK SRS S1 or S2.

Mandatory status for listed companies depends on the FCA Policy Statement, which the FCA aims to publish in autumn 2026 and which had not been published as at 1 August 2026.

How do UK SRS S1 and S2 differ from IFRS S1 and S2?

UK SRS is based on the ISSB's IFRS S1 and IFRS S2. The UK government consulted on six proposed amendments in June 2025, but two did not survive to publication; the authoritative list of final differences is Annex A of the government's consultation response, which carries no headline count. The most significant: the effective-date clauses were removed; the IFRS S1 relief allowing sustainability information to be published at a different time from the financial statements was withdrawn; the relief permitting non-climate topics to be deferred was retained but left untimed in the Standard itself (the FCA separately proposes, unconfirmed, that it run to periods beginning before 1 January 2029); SASB references were softened from 'shall refer to and consider' to 'may refer to and consider'; added paragraphs clarify how an entity states compliance when using the reliefs. The Global Industry Classification Standard requirement was dropped by the ISSB's own December 2025 change to IFRS S2, not a UK amendment.

Do UK SRS S1 and S2 replace SECR?

No.

DESNZ published the statutory post-implementation review of SECR on 26 May 2026 and its formal recommendation is to retain the SECR requirements with amendments, noting that removing SECR would risk reversing gains in transparency and board-level accountability.

On the interaction with UK SRS the government has committed only to consider how energy and emissions data reported under UK SRS interacts with SECR, with a view to reducing unnecessary duplication where possible.