On 25 February 2026, the Department for Business and Trade published the final UK Sustainability Reporting Standards - UK SRS S1 and UK SRS S2. After years of consultations, exposure drafts, and back-and-forth between government, the FRC, and industry bodies, accountants in the UK now have a concrete set of standards to work with. And whether your clients are listed companies or private SMEs, the ripple effects are coming.
TL;DR: The UK published its Sustainability Reporting Standards (UK SRS S1 and S2) on 25 February 2026, based on the ISSB's global baseline. Listed companies face mandatory climate disclosures from January 2027. Private companies and SMEs will feel the impact through supply chain data requests. Accountants need to start preparing now.
What Are UK SRS S1 and S2?
UK SRS S1 sets out general requirements for disclosing sustainability-related risks and opportunities that could affect a company's financial position, performance, or cash flows. UK SRS S2 focuses specifically on climate-related disclosures - governance, strategy, risk management, and metrics and targets. Both standards are the UK's endorsed versions of the ISSB's IFRS S1 and IFRS S2, adapted with minor UK-specific amendments (GOV.UK, 2026).
The key word there is "minor." The government kept these close to the global baseline on purpose. Companies already reporting under IFRS Sustainability Disclosure Standards will find the transition relatively straightforward. The main UK-specific changes include making industry-based guidance optional rather than mandatory, removing fixed effective dates for transitional reliefs, and subordinating the standards to the Companies Act 2006 and FCA rules (Norton Rose Fulbright, 2026).
Who Needs to Report and When?
Right now, UK SRS S1 and S2 are available for voluntary use by any entity. But "voluntary" has a short shelf life here.
The FCA published Consultation Paper CP26/5 on 30 January 2026, proposing mandatory UK SRS-aligned disclosures for companies with a UK listing. That covers around 515 primary-listed issuers across commercial, non-equity, and transition listing categories, plus 89 secondary-listed issuers (FCA, 2026). The consultation closed on 20 March 2026, and the FCA plans to publish its final policy statement in autumn 2026.
The proposed timeline is phased. UK SRS S2 climate disclosures become mandatory for accounting periods beginning on or after 1 January 2027. Scope 3 greenhouse gas emissions disclosures follow on a "comply or explain" basis from 1 January 2028. UK SRS S1 - the broader sustainability disclosures - come in on a "comply or explain" basis from 1 January 2029 (Linklaters, 2026).
What About Private Companies and SMEs?
The government has signalled it will consider extending UK SRS-based reporting to large private companies as part of a future consultation on modernising UK corporate reporting (GOV.UK, 2026). No date has been set for that consultation, but the direction of travel is clear.
In our experience, though, SMEs will not have the luxury of waiting for a mandate. Listed companies preparing for UK SRS S2 will need sustainability data from their supply chains. That means smaller businesses - suppliers, subcontractors, service providers - will start receiving data requests about carbon emissions, environmental practices, and governance policies well before any formal requirement reaches them. The government itself acknowledged this, noting that UK SRS use "is likely to have an impact on SMEs who will be asked for information by reporting entities" for value chain reporting purposes (GOV.UK, 2026).
How Does This Replace TCFD?
The Task Force on Climate-related Financial Disclosures (TCFD) formally disbanded in October 2023, with its recommendations folded into the ISSB framework. UK SRS S2 now picks up where TCFD left off. For companies already reporting under TCFD-aligned FCA rules, the shift to UK SRS S2 represents an evolution rather than a revolution. The four-pillar structure - governance, strategy, risk management, metrics and targets - remains the same.
One practical benefit: companies reporting under UK SRS S2 will satisfy existing statutory climate disclosure obligations under the Companies Act 2006 (Norton Rose Fulbright, 2026). That should reduce the burden of parallel reporting requirements, which is something the profession has been asking for.
What Should Accountants Be Doing Now?
This is where I think the profession needs a reality check. Sustainability reporting has been talked about for years, but for most practice accountants and finance teams, it has sat in the "someone else's problem" category. That changes now.
What we see most often is firms treating ESG as a specialist niche. But UK SRS integrates sustainability disclosures into general-purpose financial reports, not as standalone ESG documents. That puts it squarely in the accountant's territory. The ICAEW described sustainability as "a defining opportunity for accountancy" in early 2026, and I agree with that framing.
Practically, if you work with listed clients, start reviewing their readiness for UK SRS S2 climate disclosures now. January 2027 is closer than it feels. If your clients are private companies or SMEs, help them understand what data they will need to provide to their larger customers and investors. Getting ahead of supply chain data requests is better than scrambling to respond to them. If basic bookkeeping and data management is already a challenge, adding sustainability metrics on top will only make things harder.
The FRC is also developing a UK sustainability assurance standard based on the IAASB's ISSA 5000. A voluntary assurance oversight regime is expected by mid-2026 (ICAEW, 2026). Assurance work will follow the disclosure requirements, and firms that build capability early will be well placed when demand picks up.
The Bigger Picture
One question clients always ask about ESG reporting is whether it is worth the effort beyond the compliance box. From where I sit, the answer is yes - but only if the data is meaningful and decision-useful, not produced to fill a template. The ISSB framework, and by extension UK SRS, anchors sustainability disclosure in financial materiality. That means reporting on the sustainability matters that could genuinely affect a company's cash flows, cost of capital, or access to finance. It filters out the noise. That financial materiality lens is familiar territory for any accountant who has worked through a year-end reporting cycle.
The UK now joins a growing list of jurisdictions endorsing ISSB-aligned standards. Over 30 jurisdictions worldwide have taken steps to adopt or reference ISSB standards since their publication in June 2023 (IFRS Foundation, 2026). Global comparability matters for UK businesses competing for international investment and operating cross-border supply chains. Our advisory services can help you think through what this means for your specific situation.
Frequently Asked Questions
Are UK SRS mandatory right now?
No. As of 25 February 2026, UK SRS S1 and S2 are available for voluntary use. The FCA is expected to finalise mandatory rules for UK-listed companies in autumn 2026, with the first mandatory reporting period starting 1 January 2027 for climate disclosures under UK SRS S2.
Do UK SRS apply to private companies?
Not yet. The standards currently target listed companies. The government has indicated it will consider extending requirements to large private companies in a future consultation, but no timeline has been confirmed.
How are UK SRS different from ISSB standards?
UK SRS S1 and S2 are closely based on IFRS S1 and S2 with minor UK-specific amendments. Key differences include making SASB industry-based guidance optional instead of mandatory, removing fixed effective dates for transitional reliefs, and aligning the standards with UK law including the Companies Act 2006.
Will my SME clients need to report under UK SRS?
Not directly - at least not initially. But if your SME clients supply goods or services to listed companies, they should expect requests for sustainability data as those companies prepare their own UK SRS disclosures. Building basic ESG data collection processes now saves time later.
What happened to TCFD reporting?
TCFD formally disbanded in October 2023. UK SRS S2 replaces and builds on the TCFD framework. Companies reporting under UK SRS S2 will also satisfy existing Companies Act 2006 climate disclosure requirements, simplifying the reporting process.
If you need help understanding how UK SRS affects your reporting obligations, talk to our team. We work with UK businesses of all sizes on accounting and reporting requirements - no obligation, no jargon.