Sustainability reporting: what it is, who must report, and which rules are law

Sustainability reporting is the disclosure of environmental, social and governance information about an organisation’s activities, performance and impacts.

It is published on a regular cycle, usually once a year, and usually alongside the financial statements.

Financial reporting tells a reader what happened; sustainability reporting is mostly about what might, from the cost of a carbon price to the flood risk to a warehouse.

Under UK SRS S1 the test for what to include is whether information could reasonably be expected to influence the decisions of investors and lenders.

The EU asks a wider question, which adds the organisation’s own effects on people and the environment, and the difference is set out under materiality below.

In the UK a sustainability report is rarely a separate glossy document: the legal duties are written into named parts of the annual report.

And none of them requires an organisation to perform: SECR asks for energy use, emissions and the measures taken, not for any reduction.

The phrase is used loosely, and the looseness is expensive, because four different obligations get called “sustainability reporting” in the same meeting.

Every climate standard descended from the TCFD’s 2017 recommendations uses the same four pillars, and once you can see them most reports stop looking different from each other.

Governance is usually the shortest section, and it is the one an assurance provider tests first.

Strategy is where the risks and opportunities, their time horizons and their effect on the business model live, with scenario analysis and any transition plan.

Risk management describes how sustainability risks are found and prioritised, and whether that is the same process used for every other risk.

Metrics and targets carries the numbers: greenhouse gas emissions by scope, energy consumption, intensity ratios and any targets, with progress against them.

UK SRS S1 and S2 keep those four pillars, as do IFRS S1 and IFRS S2 before them, and the ESRS as well.

What differs between frameworks is scope, materiality and how much of the fourth pillar is prescribed, not the shape.

The two ISSB standards are read paragraph by paragraph on the IFRS S1 and IFRS S2 pages.

Five kinds of document get called a sustainability report, and only some of them answer to a law.

The statutory ones are sections of the annual report, which is why the question of placement is answered by company law rather than by preference.

A listed company may cross-refer its UK SRS disclosures to another report it publishes, under UKLR 6.6.6R(8)(c) read with UK SRS S1 Appendix B, so a standalone report can carry legal weight that way.

A CDP response is a questionnaire answer, and it is where many UK companies first assembled usable Scope 1 and 2 data.

Sector standards sit alongside, and the clearest UK case is the voluntary standard for housing providers set out on sustainability reporting standards for social housing.

The ESOS report is produced for the scheme administrator and kept in the evidence pack; it is not published, though the combined energy savings figure is.

Streamlined Energy and Carbon Reporting has applied to financial years beginning on or after 1 April 2019, under SI 2018/1155.

It reaches three populations: quoted companies, large unquoted companies and large LLPs, each with its own home in Schedule 7 to the 2008 Accounts Regulations or the LLP regulations.

A quoted company reports global energy use, Scope 1 and 2 emissions and an intensity ratio, at any size.

An unquoted company is exempt only if it meets two or more of: turnover not more than £36 million, balance sheet total not more than £18 million, not more than 250 employees.

Put the other way, it reports if it exceeds at least two of the three, and a change of side takes effect only once it has held for two consecutive years.

An unquoted company reports UK energy use from gas, electricity and transport fuel, the emissions from it, an intensity ratio, the methodology, efficiency measures and the prior year’s figures.

The de minimis is 40,000 kWh: an unquoted company that used that much UK energy or less states so in its report instead, and a quoted company has the same route without the UK qualifier.

The measured population is the reason SECR matters: the 2026 post-implementation review counts 19,900 in scope, 76% more than forecast.

The figure of 11,900 still in circulation does not appear in the review or in the evaluation behind it.

The evaluation puts suspected non-compliance at 14–23%, and the review recommends retaining SECR with amendments, not replacing it.

The Regulatory Policy Committee rated that review fit for purpose on 15 May 2026.

The test at provision level, with the group and LLP rules, is on SECR thresholds, and the routes out on SECR exemptions.

The Energy Savings Opportunity Scheme is a four-yearly energy assessment, not a public report, and it is the nearest hard deadline in UK sustainability reporting.

A large undertaking is one with at least 250 employees, or with turnover over £44 million and a balance sheet total over £38 million together, under Schedule 1 paragraphs 1 and 1A.

The test is uneven: exactly 250 employees qualifies, but exactly £44 million of turnover does not, and the money limbs only count together.

A small company that is a group undertaking of a large one is brought in with it, so the test is applied to every undertaking in the UK group.

Phase 4 status is fixed on 31 December 2026, and notification of compliance is due by 5 December 2027.

The financial figures come from the accounts for the year ending on, or in the 12 months before, 31 December 2026.

The GOV.UK ESOS overview carries the Phase 4 dates, and the provision-level reading is on ESOS Phase 4 thresholds.

The scheme in outline is on the ESOS hub, and what follows notification on the ESOS action plan.

This is the Companies Act duty most people call “TCFD reporting”, and it is in force and unamended.

It was inserted by SI 2022/31 for financial years beginning on or after 6 April 2022.

Section 414CA catches traded, banking and authorised insurance companies, insurance-market companies, AIM companies and high-turnover companies, but only where they have more than 500 employees.

A bank with 400 employees is outside it, and so is a private company with £600 million of turnover and 450 employees.

Section 414CB(2A) sets eight disclosures in the TCFD shape: governance, risk identification and management, integration, principal risks and opportunities, their effect on the business, resilience under scenarios, targets and KPIs.

Subsections (4A) and (4B) allow four of the eight, (e) to (h), to be omitted where not necessary, with a reasoned explanation; the first four cannot be.

The government has confirmed that UK SRS S2 is a national reporting framework for subsection (6), in Chapter 3 of its consultation response.

The modernising corporate reporting consultation makes no proposals on this duty (¶147), because a review of it is due by spring 2027.

The listing-rule side, which the FCA has now replaced, is separated from this duty on TCFD requirements in the UK, and the change of standard on UK SRS vs TCFD.

The Department for Business and Trade published UK SRS S1 and S2 on 25 February 2026.

S1 sets the general requirements for sustainability-related financial disclosures; S2 sets the climate-related ones, and is applied with the relevant parts of S1.

They are available for voluntary use by any entity, in the words of the government’s UK SRS guidance.

The standards carry no effective date of their own: the government removed it, so that timing would be set by whoever later requires their use.

They are built from IFRS S1 and IFRS S2, with the differences listed in Annex A of the government response, which describes them without giving a count.

Compliance with UK SRS is therefore not automatically compliance with the ISSB standards, and the reverse is not automatic either.

The standards are explained on what is UK SRS, and the dates on the UK SRS timeline.

Companies are not the only reporters: central government reports on sustainability through its annual reports and accounts.

HM Treasury’s Sustainability Reporting Guidance 2025-26, published on 17 July 2025, is mandatory for central government bodies that report under the Government Financial Reporting Manual.

It sets minimum requirements, and further reporting subject to materiality, all on a comply-or-explain basis.

The minimum requirements bind bodies with over 500 full-time-equivalent staff or over £500 million in operating income or grant funding, the same size test the Treasury uses for climate disclosure.

The 2025-26 edition narrowed the metrics, made Scope 1 and 2 a minimum requirement, left Scope 3 to materiality, and added a requirement on carbon offsets where they are used.

Other public bodies may apply it, but they answer to their own reporting authorities first.

The guidance covers environmental and climate information; social and governance topics are in the Financial Reporting Manual itself.

Materiality is one methodological decision, and it decides what goes in the report, who it is for, and how long it takes to produce.

A single-materiality assessment asks which sustainability matters could move the company’s cash flows, access to finance or cost of capital, the test in UK SRS S1.

A double-materiality assessment, the EU test in the Accounting Directive, asks that and then repeats the exercise outward, across the value chain.

GRI’s test is different again: the significance of an organisation’s impacts on the economy, environment and people, in GRI 1.

The EU’s Omnibus changes cut who reports, and did not change double materiality.

A UK group with EU operations may have to run both assessments, and the comparison is on UK SRS vs CSRD.

A UK parent is reached by Article 40a of the Accounting Directive only through its EU business.

The EU turnover limb rose from €150 million to €450 million, and must be met in each of the last two consecutive financial years.

The second limb is an EU subsidiary or branch with net turnover over €200 million: the branch figure rose from €40 million, and the old “large subsidiary” test was replaced by the same €200 million.

The obligation lands on the EU subsidiary or branch, which publishes the group’s sustainability report, not on the UK parent directly.

Separately, an EU subsidiary that is itself over 1,000 employees and €450 million reports in its own right from 2027.

If a page still shows €150 million and €40 million, it predates February 2026.

“Over 40 jurisdictions have adopted the ISSB standards” is two errors in one sentence.

The IFRS Foundation’s own figure, in its jurisdictional readiness release, is nearly 40 jurisdictions that have taken steps, and requirements in effect in 19.

The gap between the two is the gap between an intention and an obligation, which is the gap this page is about.

The Foundation’s jurisdiction listing carries no stated total, so any other count was assembled by someone else.

IFRS S1 and S2 were issued on 26 June 2023 and are held, with their guidance, in the IFRS Sustainability Standards Navigator.

None of these is required by any UK instrument, and all of them turn up in tenders, investor questionnaires and index submissions.

The GRI Universal Standards were published in October 2021 and have applied to reporting since 1 January 2023.

GRI and the IFRS Foundation set out how their standards are used together in a joint statement of 26 May 2026: complementary, meeting distinct purposes, with common disclosures aligned.

The SASB Standards are industry metrics now maintained within the IFRS Foundation, and UK SRS S1 makes reference to them permissive rather than required.

CDP runs questionnaires a company answers because an investor or customer asks it to.

For the standards themselves, the UK pair are on what is UK SRS, and the European standards on the ESRS page.

“Financial sustainability reporting” is usually a question about placement, and UK law answers it precisely.

SECR goes in the directors’ report, under Schedule 7, not in the strategic report and not in an appendix.

Climate-related financial disclosure goes in the strategic report, in the non-financial and sustainability information statement, under section 414CB.

A listed company’s UK SRS disclosures go in its annual financial report, with cross-reference permitted under UKLR 6.6.6R(8)(c).

The directors’ safe harbour in section 463 follows the location: it covers the strategic and directors’ reports, so UK SRS material placed elsewhere is not covered unless the section is widened.

The modernising corporate reporting consultation, open until 30 November 2026, proposes abolishing the directors’ report and letting companies place SECR anywhere in the first half of the annual report.

That is a proposal about SECR’s address, not its duty: who reports and what they report are untouched.

The listing-rule and Companies Act routes are compared on UK SRS vs TCFD.

This page does not rank other companies’ reports; it names the four things that separate a report that survives scrutiny from one that does not.

The basis is stated before the numbers: organisational boundary, consolidation approach, conversion-factor year, and what is excluded and why.

Restatements are visible: when the basis changes, the comparative is restated and the restatement explained, because a silently moving baseline loses a reader’s trust fastest.

Targets connect to strategy: a target with no capital allocation behind it reads as an aspiration, and both the ISSB standards and the ESRS ask what is actually being done.

Scope 3 is bounded honestly: which of the fifteen categories are measured, which estimated and which omitted, and why.

For a listed company the best examples from 2028 will include the explanations themselves, because a good explanation under UKLR 6.6.6R(7A)(b) is information in its own right.

How UK SRS S2 handles Scope 3 is on the UK SRS compliance guide.