UK Sustainability Reporting Standards Explained: What UK Businesses Need to Do Before 2027

UK companies will soon face mandatory sustainability reporting requirements. The UK Sustainability Reporting Standards (UK SRS), aligned with the ISSB framework, set out how organisations will need to disclose consistent, decision-useful climate and sustainability information.

This article was last updated on 10/03/2026

The 1 minute read

• What it is: The UK’s adoption of IFRS S1 and IFRS S2, the ISSB’s global standards for investor-focused sustainability disclosure.
• Current status: The government consultation closed in September 2025. Finalised voluntary standards were published in February with mandatory requirements to follow
• Who it’s expected to affect: Listed companies, large financial institutions, and large private companies currently doing TCFD reporting
• When mandatory reporting kicks in: Expected from 2027, subject to FCA consultation on Listing Rules
• What good preparation looks like: Audit-ready sustainability data, cross-functional governance between finance, legal, risk, operations and sustainability teams, and early voluntary disclosure to test your approach.

The final UK Sustainability Reporting Standards are expected to remain closely aligned with the ISSB framework, with only limited UK-specific adjustments.

Most changes are likely to focus on practical implementation, including transitional reliefs, timing of requirements, and flexibility around areas such as Scope 3 and value chain data.

Most CFOs and Financial Controllers we speak to are already aware of the UK Sustainability Reporting Standards. They’ve read the headlines, noted the 2027 reporting deadline, and mentally filed it under “important, but not yet urgent.” That reaction is understandable. But the window for comfortable preparation is narrowing faster than most realise.

The FCA has already published its consultation. Finalised voluntary standards were released in February, with mandatory requirements for certain entities likely to follow soon after. What was a distant regulatory horizon is now close enough to see clearly.

This article sets out what the UK SRS actually requires, who it affects and what good preparation looks like in practice.

The UK SRS is built on the International Sustainability Standards Board (ISSB) framework, a global baseline developed to give investors consistent, comparable sustainability information across companies and markets. The ISSB published its first two standards in June 2023:

• IFRS S1: General Requirements for Disclosure of Sustainability-related Financial Information
• IFRS S2: Climate-related Disclosures

To date, around 37 jurisdictions globally are adopting or integrating ISSB standards into regulation, covering over 40% of global market capitalisation and roughly 60% of global GDP.

Rather than building something from scratch, the UK is adapting these globally recognised standards for a domestic context. The independent Technical Advisory Committee reviewed both standards in detail and recommended in December 2024 that they should be endorsed for UK use, with only minor amendments. The government consultation on those adapted drafts closed in September 2025, and finalised versions are expected shortly.

The purpose of the framework is straightforward. As the UK government’s own guidance puts it:

“The ISSB’s overriding aim is to provide standards that deliver comparable and decision-useful information for investors – the disclosures required by their standards are intended to help investors to compare information between companies, supporting the efficient allocation of capital and the smooth running of capital markets.”

This is investor-facing disclosure with teeth. The November 2024 Mansion House speech signalled the government’s ambition to deliver a world-leading sustainable finance framework, with economically significant companies expected to disclose against UK SRS. The FCA will consult separately on incorporating the standards into Listing Rules for listed companies.

The framework has three main audiences

Listed companies

If your organisation is listed and already produces sustainability disclosures, UK SRS will raise the bar significantly on rigour, consistency, and the standard of evidence required. Investor expectations are already moving in this direction; they want information they can actually use to make decisions, and ISSB-aligned reporting is putting this into practice.

Large financial institutions

Banks and asset managers are caught in two directions at once: their own disclosure obligations under UK SRS, and the growing expectation that they understand and report on the sustainability profile of what’s in their portfolios. Climate-related financial risk has moved from a niche concern to a mainstream credit and investment consideration, and reporting frameworks are catching up.

Large private companies currently doing TCFD

Many companies have made strong progress through TCFD reporting, and that foundation helps. However, ISSB-aligned reporting goes further, particularly in linking sustainability to financial performance, integrating it into business strategy and expanding beyond climate. For organisations likely to fall within future mandatory UK Sustainability Reporting Standards, now is the right time to understand what remains to bridge that gap.

Regulatory clarity is the easy part. What’s harder, and where most finance and sustainability teams will face the real challenge, is delivery.

Integrating sustainability into the financial reporting process

ISSB-aligned reporting isn’t a sustainability team task that finance signs off at the end. It requires sustainability data to be treated with the same discipline as financial data – collected consistently, controlled properly, and capable of standing up to audit. For CFOs and Financial Controllers, that means actively shaping how sustainability information is gathered and governed, not just reviewing the final output.

The data problem

Most organisations that start this process discover the same thing: their sustainability data is not in the best shape. It’s often collected inconsistently across business units, and not subject to anything like the controls applied to financial data. Fixing that takes time, more time than most people budget for. Starting the data assessment now, even informally, is almost always worthwhile.

Getting the right people in the room

Credible SRS reporting requires finance, sustainability, legal, and risk functions to work together in a sustained way, often for the first time. That collaboration doesn’t happen automatically. Someone needs to own it, and in most organisations the CFO is best placed to do that, because the reporting standards demand financial-grade rigour, and finance understands what that requires.

Investor and stakeholder expectations

Better disclosure creates better questions. Investors, lenders, and increasingly supply chain partners are already asking more specific things about climate risk and sustainability strategy. Organisations that treat SRS preparation as an opportunity to get ahead of those conversations tend to find it a more useful exercise overall.

Finalised voluntary standards are due in early 2026. Mandatory requirements will follow, with the FCA consulting on Listing Rules changes and the government considering broader application under the Companies Act. 

If 2027 still feels distant, consider what’s actually involved: assessing current data and governance, identifying gaps, which could include building a full Scope 1–3 inventory, conducting climate risk assessments, updating risk management frameworks, and developing cross-industry metrics. This sits alongside building new processes, piloting disclosures, and embedding all of this across functions that have not traditionally worked closely together.

That’s not a six-month project. The organisations that handle this well tend to be those that started treating it seriously before they had to, using the time to build capability rather than scramble to meet a deadline.

A few practical starting points:

• Map your current sustainability data against what IFRS S1 (general sustainability disclosure) and IFRS S2 (climate disclosure) require
• Identify who owns the cross-functional process, and make sure it’s not just the sustainability team
• If you’re already doing TCFD, get a clear view of the large delta between that and ISSB-aligned reporting
• Consider a voluntary disclosure ahead of any mandate, it’s the best way to find weaknesses before they matter

Seismic works at the intersection of sustainability, finance, and governance, which is exactly where UK SRS implementation sits. We help organisations understand what’s actually required, where the gaps are, and how to close them in a way that’s proportionate and practical.

We start by identifying gaps against ISSB and UK SRS to establish your baseline. We then build a focused action plan to close priority risks, strengthen governance, and align reporting. Finally, we work alongside your teams to embed sustainability into operations, improve data and disclosures, and align reporting with evolving UK SRS requirements, turning compliance into strategic advantage.

If you’re a CFO or Financial Controller who wants a clear-eyed view of where your organisation stands on SRS readiness, we’re happy to start that conversation.

This blog will be updated as further regulatory developments are confirmed, including the FCA’s forthcoming consultation on Listing Rules changes and the publication of finalised UK SRS standards.