UK SRS S1: General Requirements for Disclosure of Sustainability-related Financial Information

What UK SRS S1 actually requires

UK SRS S1 establishes how an entity discloses information about all sustainability-related risks and opportunities that could reasonably be expected to affect its cash flows, access to finance, or cost of capital over the short, medium, or long term1. It is not a climate-specific standard — climate disclosures are covered by UK SRS S2.

S1 standard covers the full universe of sustainability matters: biodiversity, water and marine resources, workforce, value chain emissions, governance, and any other sustainability factor that meets the materiality threshold.

The standard runs to 86 paragraphs across five appendices, structured around the same four pillars used by the IFRS Sustainability Disclosure Standards and the now-disbanded UK SRS vs TCFD:

Each pillar carries specific disclosure requirements that must be applied in conjunction with any other sustainability reporting standards that specifically addresses the relevant risk or opportunity.

Materiality — the single materiality basis

UK SRS S1 applies a single materiality basis. Information is material if its omission, misstatement, or obscuring could reasonably be expected to influence the decisions that primary users (existing and potential investors, lenders, and other creditors) make on the basis of the entity's general purpose financial reports1.

The reference point is enterprise value: how sustainability matters affect the entity's prospects, not the entity's effects on the wider environment or society. This is a critical point of difference from the CSRD comparison and its underlying European Sustainability Reporting Standards (ESRS), which apply a double materiality basis5.

Under double materiality, entities must also disclose how their activities affect people and the environment regardless of financial impact. S1 standard keeps the materiality scope deliberately narrower and financially-anchored, in line with the IFRS Foundation's ISSB framework3.

The six UK-specific amendments

The UK SRS were developed by adapting IFRS S1 and IFRS S2 for the UK context, based on recommendations from the UK Sustainability Disclosure Technical Advisory Committee (TAC). Six amendments distinguish UK SRS S1 from IFRS S1:

1. No effective date. All references to a fixed effective date have been removed. UK SRS are available for voluntary use immediately; mandatory application will be set out separately by the FCA (for listed companies) or under the Companies Act (for other in-scope entities).

2. Removal of delayed reporting transition relief. IFRS S1 paragraph E4 permitted delayed publication of sustainability disclosures relative to financial statements. UK SRS S1 removes this — disclosures must be published at the same time as the related financial statements.

3. Extended climate-first transitional relief. IFRS S1 allows a one-year grace period during which an entity may disclose only climate-related information. UK SRS S1 extends this to two years, giving UK preparers more time to build non-climate sustainability data infrastructure.

4. SASB Standards optional, not mandatory. IFRS S1 requires entities to "shall refer to and consider" the SASB Standards when identifying sustainability-related risks. UK SRS S1 softens this to "may refer to and consider," making SASB application permissive rather than required8.

5. Industry classification flexibility. IFRS S2 mandates the use of the Global Industry Classification Standard (GICS) for financed emissions disclosures. UK SRS S2 permits alternative classification systems where appropriate.

6. Transitional reliefs tied to mandatory use. Time references for transitional reliefs have been removed from the standard text. The availability of reliefs will be set out in the regulations or rules that introduce mandatory reporting.

Connectivity to financial statements

One of the most significant requirements in general sustainability disclosures is the connectivity principle (paragraphs 21–24, and appendix paragraphs B39–B44)1. An entity must provide its sustainability-related financial disclosures in a manner that enables users to understand the connections between sustainability matters and the entity's financial statements.

Specifically:

• Connections between disclosures on governance, strategy, risk management, and metrics and targets
• Connections between narrative and quantitative information
• Connections across various sustainability-related risks and opportunities
• Consistency of data and assumptions between the sustainability disclosures and the related financial statements

This connectivity requirement is one of the most material differences from the legacy TCFD framework, which encouraged but did not mandate explicit financial statement linkage. Under UK SRS S1, the connection must be explicit and verifiable1.

For example, if an entity discloses a transition risk to its business model, the related current and anticipated financial effects must be quantified or, where genuine measurement uncertainty exists, explained qualitatively with reasoning.

Timing, location, and statement of compliance

UK SRS S1 specifies several practical requirements about when and where sustainability information is disclosed:

Timing — disclosures must cover the same reporting period as the related financial statements and be published at the same time (paragraph 64)1.

Location — disclosures must form part of the entity's general purpose financial reports. They may be included in the management commentary, strategic report, integrated report, or similar required report (paragraphs 60–62)1. Cross-referencing to other published reports is permitted under specified conditions (paragraph 63 and B45–B47)1.

Statement of compliance — an entity whose disclosures comply with all requirements must make an explicit and unreserved statement of compliance with UK Sustainability Reporting Standards (paragraph 72)1. An entity may not claim compliance unless every applicable requirement has been met.

Use of transition reliefs — an entity may still assert compliance with UK SRS S2 while using specified exemptions, provided it discloses that use. Different rules apply for S1 exemptions under paragraph E3 (paragraph 73A)1.

Who must apply UK SRS S1, and when

UK SRS S1 is currently available for voluntary use by any UK entity, listed or private, of any size. Mandatory application will be introduced in phases through separate legislation and regulation.

The FCA's Consultation Paper CP26/52 — Aligning Listed Issuers' Sustainability Disclosures with International Standards, published 30 January 2026 and closed 20 March 2026, proposes:

• Mandatory UK SRS S2 (climate) reporting for commercial companies (UKLR 6), non-equity shares and non-voting equity shares (UKLR 16), and transition category (UKLR 22) — approximately 500 in-scope listed issuers
• Scope 3 emissions on a comply-or-explain basis with an optional one-year deferral
• Wider UK SRS S1 (non-climate sustainability) reporting on a comply-or-explain basis with an optional two-year deferral
• Required statement on whether and where a transition plan has been published
• Required statement on whether voluntary assurance has been obtained

A final FCA Policy Statement is expected in autumn 2026, with rules coming into force for accounting periods beginning on or after 1 January 2027. The first mandatory reports would therefore be published in spring 2028 for entities with December 2027 year-ends.

Assurance — ISSA (UK) 5000

The Financial Reporting Council published the International Standard on Sustainability Assurance (UK) 5000 — ISSA (UK) 5000 — on 12 November 20254, providing the framework for assurance engagements over sustainability information.

The standard is effective for assurance engagements on sustainability information reported for periods beginning on or after 15 December 2026. ISSA (UK) 5000 is a UK adaptation of the International Auditing and Assurance Standards Board's (IAASB) ISSA 5000, with one minor amendment restricting the use of direct assistance by internal auditors in sustainability assurance engagements4.

It covers both limited and reasonable assurance engagements, and applies whether or not the assurance practitioner is also the entity's auditor. An interim register of sustainability assurance practitioners is expected from the FRC by mid-2026.

Under CP26/5, the FCA does not propose mandating assurance for in-scope listed issuers in the initial phase2. However, listed issuers will be required to disclose whether voluntary assurance has been obtained and the scope of any such engagement.

How UK SRS S1 differs from the EU CSRD and ESRS

The structural differences from the EU regime are more significant than the differences from IFRS S1:

Materiality basis — UK SRS S1 applies single (financial) materiality. CSRD applies double materiality (financial and impact)5.

Scope — UK SRS S1 is investor-focused; CSRD includes a wider stakeholder lens.

Audience — UK SRS S1 disclosures are intended for primary users of general purpose financial reports. CSRD/ESRS disclosures include workers, communities, civil society, and other stakeholders5.

Assurance — UK SRS uses ISSA (UK) 5000 with optional initial application. CSRD requires limited assurance from the outset, transitioning to reasonable assurance4.

Sector standards — UK SRS does not include mandatory sector-specific ESRS-style standards. SASB may be used voluntarily8.

For UK groups with EU subsidiaries subject to CSRD, the practical reality is that two separate but related reporting regimes apply. The UK government has signalled awareness of interoperability concerns and engaged with the IFRS Foundation's work on alignment, but no formal equivalence mechanism is currently proposed.

How UK SRS S1 builds on TCFD

The Task Force on Climate-related Financial Disclosures (TCFD) was formally disbanded in October 2023 following the ISSB's publication of IFRS S1 and S2. UK SRS S1 and S2 are the regulatory successor to TCFD-aligned listing rules.

Compared to TCFD:

• Wider scope — TCFD addressed only climate. UK SRS S1 addresses all sustainability matters meeting the materiality threshold.
• Connectivity — TCFD encouraged but did not require explicit links to financial statements. UK SRS S1 mandates connectivity.
• Specificity — TCFD was principles-based. UK SRS S1 prescribes detailed disclosure requirements including quantification of current and anticipated financial effects.
• Industry guidance — TCFD provided supplementary guidance for financial sector and four non-financial sectors. UK SRS S1 references SASB Standards as a permissive sector resource.

Listed companies currently reporting under TCFD-aligned UK Listing Rules will need to upgrade their data, governance, and disclosure infrastructure to meet UK SRS requirements once mandatory.

Practical implementation — where companies typically struggle

Based on Big 4 and professional services commentary on early voluntary adoption, four implementation areas consistently emerge as the hardest:

1. Materiality assessment that meets the connectivity bar

The connectivity principle requires materiality assessments to be tied to the financial statements. Many companies have historical sustainability materiality assessments built on stakeholder consultation or impact frameworks; these typically need to be reworked to align with the financial materiality basis required by UK SRS S11.

2. Scope 3 emissions data along the value chain

While Scope 3 is specifically a UK SRS S2 requirement, the data infrastructure overlaps with S1 obligations on value chain disclosure. Companies report this as the single most resource-intensive workstream, often requiring 12–18 months of supplier engagement before full disclosure is achievable.

3. Governance integration

UK SRS S1 paragraphs 26–27 require detailed disclosure of how sustainability oversight is reflected in board mandates, role descriptions, skills assessments, and remuneration linkage1. Many boards have governance processes that work in practice but lack the documentation trail to evidence the specific requirements of paragraph 27.

4. Financial effect quantification

Paragraphs 34–40 require quantitative disclosure of the current and anticipated financial effects of sustainability risks and opportunities1. The standard permits qualitative-only disclosure where measurement uncertainty is genuine, but the bar for invoking that relief is high. Companies should expect external assurance to scrutinise the basis on which quantification was, or was not, attempted.

What to do now if you are in scope

The pragmatic path forward depends on whether you are an in-scope listed issuer (likely mandatory from 1 January 2027) or a large private entity (likely subject to MCR consultation in late 2026, with mandatory dates to be set thereafter):

For listed issuers in scope of CP26/5:

• Map your existing TCFD-aligned disclosures against UK SRS S2 requirements; identify data, governance, and disclosure gaps
• Establish a cross-functional working group spanning finance, sustainability, legal, and risk
• Begin voluntary UK SRS S2 reporting in your 2026 annual report cycle if practical
• Engage assurance providers early to scope a voluntary or mandatory assurance approach
• Monitor the FCA Policy Statement in autumn 2026 for confirmed scope and timeline

For private entities likely in scope of MCR:

• Review the UK SRS S1 standard in full to understand the disclosure architecture
• Track the MCR consultation expected later in 2026 for scope, thresholds, and timeline
• Run a materiality assessment aligned to the UK SRS S1 single materiality basis
• Build initial Scope 1 and Scope 2 emissions data infrastructure; begin Scope 3 mapping
• Consider voluntary partial adoption (governance and metrics disclosures) to build organisational capability before mandatory application