UK SRS S1 and S2: The Timeline, Who Reports First, and How to Prepare

UK sustainability reporting is in the middle of its biggest structural change since TCFD-aligned disclosure was written into the listing rules in 2021. On 25 February 2026 the government published the final UK Sustainability Reporting Standards, UK SRS S1 and UK SRS S2, endorsing the ISSB's IFRS S1 and IFRS S2 for use in the UK with a small number of deliberate amendments.¹ Five weeks earlier, the FCA had opened consultation CP26/5 proposing to retire its TCFD-aligned listing rules and require listed companies to report against UK SRS S2 for accounting periods beginning on or after 1 January 2027.²

The practical question for a UK reporting team in mid-2026 is what changes between this year's report and the one it will publish for FY2027, so this guide runs timeline-first, separating what is final from what is still proposed as of July 2026.

Where are UK companies reporting from today?

Three regimes define the current baseline, and understanding them matters because UK SRS replaces only one of them.

FCA TCFD-aligned listing rules. Since accounting periods beginning 1 January 2021 for premium-listed commercial companies, and 1 January 2022 for standard-listed companies, listed issuers have had to include a statement in the annual financial report saying whether their disclosures are consistent with the TCFD's recommendations and recommended disclosures, and if not, why not, and what they plan to do about it.⁵ It is the comply-or-explain regime most listed teams have worked under for four or five reporting cycles, and the one the FCA now proposes to retire.

Companies Act climate-related financial disclosures (CFD). Separately, the Companies (Strategic Report) (Climate-related Financial Disclosure) Regulations 2022 and the parallel LLP regulations require certain large companies and LLPs to make TCFD-style climate disclosures in the Strategic Report, for financial years starting on or after 6 April 2022.⁷ These regulations sit in company law, not the listing rules, and are unaffected by CP26/5.³

SECR. Streamlined Energy and Carbon Reporting has required quoted companies and large unquoted companies and LLPs to disclose energy use, greenhouse gas emissions and an intensity ratio in the Directors' Report since April 2019.⁶ SECR continues; the interaction is mapped below.

The practical takeaway: if you are listed, one of your three regimes is about to be swapped out, the other two stay put.

What are the UK Sustainability Reporting Standards (UK SRS S1 and S2)?

UK SRS S1 and UK SRS S2 are the UK-endorsed versions of the ISSB's two global baseline standards. UK SRS S1 (General Requirements for Disclosure of Sustainability-related Financial Information) sets the architecture: an entity discloses material information about the sustainability-related risks and opportunities that could reasonably be expected to affect its prospects, organised under four pillars, governance, strategy, risk management, and metrics and targets. UK SRS S2 (Climate-related Disclosures) applies that architecture to climate specifically, adding requirements including Scope 1, 2 and 3 greenhouse gas emissions, climate scenario analysis, industry-based metrics and transition plan disclosure.

The four-pillar structure is inherited directly from the TCFD. Governance covers board and management oversight, skills and controls; strategy covers effects on the business model, financial planning and resilience, including scenario analysis and transition plans; risk management covers how risks and opportunities are identified, assessed, prioritised and integrated; metrics and targets covers GHG emissions, industry-based metrics and progress against targets. That inheritance is why the government and FCA describe the move as an evolution rather than a rebuild, the ISSB standards "build and expand on" the TCFD recommendations.⁸

How does UK SRS differ from IFRS S1 and S2? The UK amendments

The exposure drafts published in June 2025 proposed six amendments to the ISSB baseline; the government response of 25 February 2026 confirmed the approach, with some refinement.^3,10 For groups also reporting under ISSB standards elsewhere, these are the deltas:

• The first-year timing relief was removed. IFRS S1 lets first-time reporters publish sustainability disclosures later than the financial statements. UK SRS deletes this relief, keeping sustainability and financial reporting on the same timetable from day one.³
• Transition reliefs lose their fixed time limits. The ISSB reliefs allowing climate-only reporting ("climate-first") and deferral of Scope 3 disclosure carry one-year limits in IFRS S1/S2. UK SRS removes the time references entirely: voluntary reporters can use the reliefs indefinitely; time limits will be imposed by whichever regulator mandates the standards, as the FCA now proposes.³
• SASB becomes optional. Where IFRS S1 says preparers shall refer to and consider the SASB Standards when identifying disclosures, UK SRS says they may.⁹
• Effective-date clauses were deleted. UK SRS itself specifies no effective date; dates will be set in FCA rules or company law when reporting is mandated.³
• The ISSB's December 2025 targeted amendments are incorporated, including clarification that Scope 3 Category 15 disclosure can be limited to financed emissions, permission to use classification systems other than GICS for financed-emissions breakdowns, and related reliefs for derivatives and insurance-associated emissions.^3,9
• A pragmatic mechanism for financed emissions. Financial institutions that cannot reliably estimate financed emissions for the same reporting period may use information from a different period, or explain non-compliance, provided they disclose the reasons and their remediation plans.⁹

Two consequences follow. First, a UK SRS-compliant report is very close to an IFRS S1/S2-compliant report, helpful for dual-listed groups and for comparability with the 30-plus jurisdictions adopting ISSB standards. Second, reliefs must be claimed precisely: a company applying the climate-first exemption cannot claim full compliance with UK SRS S1, only with S1 "to the extent it relates to climate".⁹

Who must report under UK SRS, and when?

As of July 2026, the honest answer is: nobody must, yet, but listed companies should plan as if FY2027 is real.

Now: voluntary use by any entity

The final standards are available for voluntary application by any UK entity for any reporting period, with the climate-first and Scope 3 reliefs usable without time limit.¹ Early voluntary reporting lets you rehearse the full disclosure set while errors are cheap, and investors increasingly ask for ISSB-aligned information regardless of mandate.

From 2027 (proposed): FCA-listed companies

CP26/5, published on 30 January 2026 with the consultation closing on 20 March 2026, proposes replacing the TCFD-aligned listing rules with UK SRS-based requirements for companies in five UK listing categories: commercial companies (UKLR 6), secondary listings (UKLR 14), depositary receipts (UKLR 15), non-equity and non-voting equity shares (UKLR 16) and the transition category (UKLR 22), with some variations by category.² The proposed sequencing is deliberately phased:⁴

• Accounting periods beginning on or after 1 January 2027: mandatory disclosure under UK SRS S2, the climate standard, with the exception of Scope 3 emissions.
• Periods beginning on or after 1 January 2028: Scope 3 emissions disclosure on a comply-or-explain basis, a strict version of it, examined in the Scope 3 section below.
• Periods beginning on or after 1 January 2029: the wider, non-climate sustainability disclosures under UK SRS S1 on a comply-or-explain basis.

For a calendar-year company, the effective date translates into a publication date like this:

The rules bite on the accounting period, not the publication date, a calendar-year listed company reports on FY2027 and publishes in 2028.

Later: other companies via the Companies Act

For large private companies, the government has deferred decisions to a broader "modernising corporate reporting" exercise, with a consultation promised later in 2026.³ Nothing about UK SRS currently changes obligations under the 2022 climate-related financial disclosure regulations. The grace period is genuine but not indefinite, and many private companies will feel the standards sooner through the value chain, as listed customers compiling Scope 3 inventories ask their suppliers for data.

The FCA intends to finalise its rules in 2026, policy statement in the autumn, rules in force on 1 January 2027.^2,9 Until then, every 2027+ date above is a proposal: firm enough to plan against, not yet law.

Does UK SRS replace TCFD? What actually changes in practice

For listed companies, yes, CP26/5 proposes that UK SRS-based rules replace the TCFD-aligned listing rules outright.⁵ The FCA is explicit that disclosure quality improved consistently under TCFD, and equally explicit that the new regime is "an uplift in requirements".^4,8 The architecture is familiar; the obligations are harder in specific, plannable ways.

Row by row, the pattern is the same: judgement calls that TCFD left open, the same four pillars, but now with defined terms and application guidance behind them, are specified, and gaps that could previously be explained in a paragraph must be itemised against specific requirements. Four further dimensions the diagram does not show:

That specificity is precisely what makes the new regime more valuable to investors, and more demanding of the evidence and audit trail behind each disclosure.

What does UK SRS require for climate scenario analysis?

Scenario analysis is where many TCFD reports were weakest, and it is one of the clearest uplifts. UK SRS S2 requires an entity to assess its climate resilience using climate-related scenario analysis, with an approach commensurate with its circumstances, its exposure, skills, and resources. In practice a credible first-cycle exercise for a listed company means:

• at least two, preferably three, scenarios spanning genuinely different futures, typically a 1.5°C-aligned rapid-transition pathway, an intermediate 2°C pathway, and a 3°C+ limited-policy-action world where physical risks dominate;
• a documented method: which scenarios, from which sources, over which time horizons, applied to which parts of the business;
• the resilience conclusions the board actually drew, and how they changed strategy or financial planning, not a generic description of the technique.

Do not treat scenario analysis as a standalone consultancy deliverable bolted on at year end: under UK SRS it feeds the strategy pillar directly, boards will be asked how the results informed decisions, and it should start in the first half of the reporting year, not the last quarter.

Transition plans: what does UK SRS expect, and where does the TPT framework fit?

Neither UK SRS nor the proposed FCA rules require you to have a transition plan. UK SRS S2 requires an entity that has one to disclose information about it, key assumptions, dependencies, and how it will resource the plan. The FCA goes a step further for listed companies: under CP26/5, a company must state whether it has disclosed a transition plan and where it can be found, or explain why not.⁴ The requirement is honesty about whether one exists, not the plan itself.

The natural methodology is the Transition Plan Taskforce (TPT) Disclosure Framework, published in October 2023 and now maintained by the IFRS Foundation as official guidance for transition plan disclosure under IFRS S2, with sector guidance and mappings to IFRS S2 and ESRS.¹² Its structure, ambition, action, accountability, remains the benchmark UK investors recognise.

Separately, the government consulted between 25 June and 17 September 2025 on implementing its manifesto commitment for UK-regulated financial institutions and FTSE 100 companies to develop credible transition plans aligned with 1.5°C; as of July 2026 the response is still pending.¹¹ The direction of travel is clear enough that large listed companies should treat a TPT-aligned plan as a when, not an if.

Scope 3 under UK SRS: requirements, reliefs and the comply-or-explain trap

Scope 3 is the requirement reporting teams worry about most, so it is worth being precise about the reliefs.

• Voluntary reporters can defer Scope 3 disclosure indefinitely under the UK amendment removing the relief's time limit, until a regulator sets one.³
• Listed companies, under the FCA's proposals, are exempt from Scope 3 for periods beginning in 2027, with comply-or-explain applying from periods beginning on or after 1 January 2028.⁴
• Financial institutions get the targeted financed-emissions flexibilities described under the UK amendments above, Category 15 limited to financed emissions, non-GICS classifications, different-period data where needed.⁹

The trap is reading "comply-or-explain" as "optional". The FCA's version has teeth: an explanation must identify the exact UK SRS S2 paragraphs not applied, the reasons, and the steps and timeframes for closing the gap.⁴ Write that explanation once and you have publicly committed to a Scope 3 roadmap that next year's report will be judged against. Most companies will find it less painful to build the inventory than to manage a public multi-year excuse: a full 15-category screening in the first year, even one leaning on spend-based estimates for the long tail, establishes which categories are material and where primary data is worth pursuing.

How does UK SRS interact with SECR?

UK SRS does not replace SECR, and no proposal on the table would change that before the government's promised corporate reporting consultation. Quoted companies and large unquoted companies and LLPs must continue to disclose energy consumption, emissions and intensity metrics in the Directors' Report under the 2018 SECR framework.⁶

For a listed company from FY2027 this means two regimes in the same annual report: SECR's energy-and-emissions disclosures, and UK SRS S2's fuller climate disclosure. Handled naively, that means two teams calculating similar numbers with different boundaries and inconsistent totals, a gift to any sceptical reader. Handled well, it is one GHG inventory with one methodology note feeding both outputs: SECR's energy use and Scope 1 and 2 figures are a subset of the UK SRS S2 metrics pillar, both can run on the same government conversion factors, updated annually each June, the 2026 set published on 11 June 2026¹³, and one intensity ratio serves both. Reconcile the boundaries once, document the choice, and reuse it.

How should a UK reporting team prepare in the first year?

Assume the FCA confirms broadly what it consulted on. A calendar-year listed company then has the remainder of 2026 to prepare for a reporting period that starts on 1 January 2027. A realistic sequence:

• Gap-assess your current TCFD report against UK SRS S2, paragraph by paragraph (Q3 2026). Map every existing disclosure to the UK SRS paragraph it satisfies and list what is missing, typically quantified financial effects, industry-based metrics, complete Scope 3, and decision-useful scenario analysis.
• Fix the GHG inventory first (Q3–Q4 2026). Scope 1 and 2 must be robust from year one, and a Scope 3 screening determines what your 2028 comply-or-explain position will be. Data contracts with facilities, fleet, finance and procurement take longer than the calculations.
• Run scenario analysis during 2026, not after FY2027 closes. The board needs time to engage with the results and act on them, because UK SRS asks what you concluded and did, not merely what you modelled.
• Decide your transition plan posture. Publish TPT-aligned, publish partial, or explain, each is available, but the statement must be board-approved and defensible.
• Build the governance evidence as you go. The governance pillar requires disclosure of board and committee oversight, and the assurance disclosure means your data lineage should withstand third-party scrutiny. An audit trail reconstructed in January is a fiction; one accumulated across the year is evidence.
• Dry-run the full report on FY2026 data. A voluntary or internal UK SRS-format report this year is the cheapest way to find the gaps that matter, while the standards' reliefs are still generous.

Costs concentrate wherever this is done manually, consultants re-mapping disclosures each cycle, spreadsheets holding the inventory together, version-control chaos at sign-off. That is a tooling problem before it is a headcount problem: purpose-built platforms such as EcoLedger run the Scope 1–3 inventory, the scenario analysis and the paragraph-level standard mapping in one governed workflow, so the audit trail accumulates as a by-product of the work.

The one-line summary for your next planning meeting: the standards are final, the FY2027 start date is a proposal, and the sensible strategy is to prepare for the proposal while being early is still cheap.

Frequently asked questions

Is UK SRS mandatory in 2026?

No. The final UK SRS S1 and S2 published on 25 February 2026 are voluntary for any entity.¹ Mandatory application needs separate regulatory action: the FCA has proposed listing-rule requirements from accounting periods beginning on or after 1 January 2027, with Companies Act legislation for other companies to follow later.²

Does UK SRS replace TCFD reporting in the UK?

For listed companies, yes, the FCA proposes replacing its TCFD-aligned listing rules with UK SRS-based requirements from 1 January 2027.⁵ Existing TCFD work carries over because UK SRS S2 builds on the four-pillar TCFD architecture, but core climate disclosures become mandatory rather than comply-or-explain. The Companies Act climate-related financial disclosure regulations continue unchanged for now.⁷

Who must report under UK SRS first?

Under the FCA's proposals in CP26/5, companies in the UKLR 6, 14, 15, 16 and 22 listing categories report first, for accounting periods beginning on or after 1 January 2027, meaning first reports published in 2028 for calendar-year companies.^2,4 Private companies are not yet in scope.

What is the difference between UK SRS and the ISSB standards IFRS S1 and S2?

UK SRS S1 and S2 are IFRS S1 and IFRS S2 endorsed for UK use with limited amendments: the first-year timing relief was removed, the fixed time limits on the climate-first and Scope 3 transition reliefs were removed (regulators will set them), SASB references changed from "shall" to "may" consider, effective-date clauses were deleted, and the ISSB's December 2025 targeted amendments were incorporated.^3,9

Are Scope 3 emissions mandatory under UK SRS?

UK SRS S2 requires Scope 1, 2 and 3 disclosure, but the FCA proposes exempting listed companies from Scope 3 in the first year, with comply-or-explain applying from periods beginning on or after 1 January 2028, any explanation must name the specific paragraphs not applied, give reasons and set out a timetable for compliance.⁴ Voluntary reporters can use the Scope 3 relief indefinitely.

Does UK SRS replace SECR?

No. Streamlined Energy and Carbon Reporting continues as a separate Directors' Report requirement for quoted companies and large unquoted companies and LLPs.⁶ The underlying data overlaps heavily, so one well-governed GHG inventory can feed both regimes.

Do UK SRS reports need to be assured?

Not under current proposals, but listed companies would have to disclose whether they obtained third-party assurance and, if so, the provider, scope and assurance standards used.⁴ The government consulted separately in 2025 on regulating sustainability assurance providers, so expectations are likely to rise.¹¹

References

1. Department for Business and Trade, UK Sustainability Reporting Standards (final UK SRS S1 and S2 published 25 February 2026 for voluntary use), accessed July 2026.
2. Financial Conduct Authority, CP26/5: Aligning listed issuers' sustainability disclosures with international standards, published 30 January 2026, consultation closed 20 March 2026, accessed July 2026.
3. Department for Business and Trade, Government response to the consultation on UK Sustainability Reporting Standards, 25 February 2026, accessed July 2026.
4. Linklaters Sustainable Futures, UK SRS: FCA proposes mandatory climate disclosures from 2027, except for Scope 3 emissions, 2026, accessed July 2026.
5. Financial Conduct Authority, Climate-related reporting requirements (TCFD-aligned listing rules from FY2021/FY2022 and their proposed replacement), accessed July 2026.
6. HM Government, Environmental reporting guidelines: including Streamlined Energy and Carbon Reporting requirements, accessed July 2026.
7. Department for Business and Trade, Climate-related financial disclosures for companies and LLPs (regulations applying to financial years starting on or after 6 April 2022), accessed July 2026.
8. KPMG, FCA CP26/5 – from TCFD to UK SRS: sustainability reporting for listed companies, 2026, accessed July 2026.
9. Linklaters Sustainable Futures, UK Government publishes final versions of UK SRS, February 2026, accessed July 2026.
10. PwC UK, UK government endorses UK sustainability reporting standards, 2026, accessed July 2026.
11. Department for Energy Security and Net Zero, Climate-related transition plan requirements, consultation 25 June – 17 September 2025 (response pending), accessed July 2026.
12. IFRS Foundation, Transition Plan Taskforce resources, IFRS Sustainability Knowledge Hub, accessed July 2026.
13. Department for Energy Security and Net Zero, Government conversion factors for company reporting of greenhouse gas emissions (updated annually; 2026 factors published 11 June 2026), accessed July 2026.