ISSB · IFRS S1 and S2
ISSB standards: IFRS S1, IFRS S2 and the UK route
The ISSB standards are IFRS S1 and IFRS S2, issued by the International Sustainability Standards Board in June 2023.
They are the baseline the UK endorsed as UK SRS S1 and S2, but they do not apply in the UK directly.
The two standards
IFRS S1 and IFRS S2: general and climate
| Standard | What it covers | Effective under IFRS |
|---|---|---|
| IFRS S1 | General requirements for disclosing sustainability-related financial information: the risks and opportunities that could affect a company’s prospects | Periods beginning on or after 1 January 2024; early application only together with IFRS S2 |
| IFRS S2 | Climate-related disclosures, building on the TCFD recommendations, with industry-based requirements derived from the SASB Standards | Periods beginning on or after 1 January 2024; amended by the ISSB in December 2025 |
IFRS S1 is the frame: it says what a company must disclose about any sustainability-related risk or opportunity that could reasonably be expected to affect its prospects.
IFRS S2 is the first topic standard, for climate.
The December 2025 amendments to IFRS S2 were the ISSB’s, not the UK’s; UK SRS S2 is based on IFRS S2 as amended then.
For what the climate standard asks of a UK reporter, see UK SRS S2; for the general requirements, see UK SRS S1.
Where the ISSB came from
Built on the TCFD, the CDSB and SASB
The IFRS Foundation announced the ISSB on 3 November 2021 at COP26 in Glasgow.
It operates alongside, but independently from, the IASB, which sets the accounting standards; “IFRS” on its own can mean either.
The CDSB was consolidated into the IFRS Foundation on 31 January 2022, and the ISSB took responsibility for the SASB Standards in August 2022.
The TCFD was not merged into anything: the FSB said its October 2023 status report was its final task and that it would be disbanded.
The monitoring of companies’ climate-related disclosures passed to the IFRS Foundation from 2024.
How the TCFD’s four pillars map to UK SRS is on our TCFD vs UK SRS page.
Dates from the owners’ own pages
| Date | Event |
|---|---|
| 3 Nov 2021 | IFRS Foundation Trustees announce the ISSB at COP26 |
| 31 Jan 2022 | CDSB consolidated into the IFRS Foundation |
| Aug 2022 | ISSB takes responsibility for the SASB Standards |
| June 2023 | IFRS S1 and IFRS S2 issued |
| Oct 2023 | TCFD publishes its final status report and disbands |
| Dec 2025 | ISSB amends IFRS S2 |
Sources: IFRS Foundation; CDSB; FSB
Who uses them
Taking steps is not the same as in effect
The IFRS Foundation keeps a directory of use by jurisdiction, with two kinds of entry.
A profile is published once a jurisdiction’s approach is finalised; a snapshot is a preview of proposals that may still change.
On 24 February 2026 the Foundation said that nearly 40 jurisdictions were taking steps to use the standards, and that requirements had already come into effect in 19.
The two figures measure different things, so neither should be presented as the number of places where companies report.
Jurisdiction counts move often and the Foundation’s own pages do not always agree.
Quote a figure with its date and source, and keep “taking steps” apart from “in effect”.
The UK route
The UK uses the ISSB standards through UK SRS
The Department for Business and Trade published UK SRS S1 and S2 on 25 February 2026 as the UK-endorsed versions of IFRS S1 and S2.
They went through the government’s endorsement framework, with a technical and a policy committee.
The government’s consultation response maps every UK change in its Annex A and gives no total count of amendments, so we do not give one either.
One visible change: the effective-date clauses were removed, so “1 January 2024” is an IFRS date and does not apply to UK SRS.
New or amended ISSB standards, such as any future nature or human capital standard, would not apply in the UK automatically; each would need UK endorsement first.
Under the FCA’s final rules in PS26/19, listed companies in UKLR 6, 14, 15, 16 and 22 report against UK SRS on a comply-or-explain basis for accounting periods beginning on or after 1 January 2027.
Every other UK entity may use UK SRS voluntarily.
For the paragraph-level differences, see UK SRS vs IFRS S1 and S2; for who is in scope, see who must comply with UK SRS.
In practice
What a UK reporting team should work from
A UK listed company reports against UK SRS, so its working text should be the UK standards, not the IFRS versions.
A UK subsidiary of a group reporting under IFRS S1 and S2 elsewhere can reuse much of the group’s work, but should check the Annex A differences before relying on group wording.
The data gaps a first-year reporter usually has to close are set out in our UK SRS gap analysis, and the formats are in our UK SRS reporting templates.
Frequently asked
Questions people ask
What are the ISSB standards?
The sustainability disclosure standards issued by the International Sustainability Standards Board: IFRS S1 General Requirements for Disclosure of Sustainability-related Financial Information, and IFRS S2 Climate-related Disclosures. Both were issued in June 2023 and are effective under IFRS for annual reporting periods beginning on or after 1 January 2024.
What is the difference between IFRS S1 and IFRS S2?
IFRS S1 sets the general requirements for disclosing sustainability-related risks and opportunities that could affect a company’s prospects. IFRS S2 sets the specific requirements for climate-related disclosures, building on the TCFD recommendations and including industry-based requirements derived from the SASB Standards. IFRS S1 may be applied early only if IFRS S2 is also applied.
Do the ISSB standards apply in the UK?
Not directly. The UK uses them through UK SRS S1 and S2, which the Department for Business and Trade published on 25 February 2026 after its endorsement process. New or amended ISSB standards do not apply in the UK automatically; each needs UK endorsement first. Under the FCA’s final rules in PS26/19, listed companies in UKLR 6, 14, 15, 16 and 22 report against UK SRS on a comply-or-explain basis for periods beginning on or after 1 January 2027.
Did the ISSB replace the TCFD?
The TCFD disbanded in October 2023 after its final status report, and the FSB asked the IFRS Foundation to take over monitoring of companies’ climate-related disclosures. IFRS S2 integrates and builds on the TCFD recommendations. The CDSB was consolidated into the IFRS Foundation in January 2022, and the ISSB took responsibility for the SASB Standards in August 2022.
How many countries use the ISSB standards?
The IFRS Foundation said on 24 February 2026 that nearly 40 jurisdictions were taking steps to use the standards and that requirements had already come into effect in 19. Taking steps is not the same as reporting being in effect, so the two figures should not be merged.
Sources
Primary sources
Every figure, date and status on this page traces to the instrument’s owner. Secondary commentary is never the source for a number.
- IFRS FoundationInternational Sustainability Standards Board — group page
Formed 3 November 2021 at COP26; IFRS S2 issued June 2023.
- IFRS FoundationWho we are
The ISSB operates alongside — but independently from — the IASB.
- IFRS FoundationIFRS S1 General Requirements — standard page
Effective from 1 January 2024; early application only with IFRS S2.
- IFRS FoundationIFRS S2 Climate-related Disclosures — standard page
Builds on the TCFD recommendations; industry-based requirements from SASB.
- IFRS FoundationSASB Standards
ISSB responsible since August 2022; 77 industries.
- CDSB (legacy site)CDSB consolidated into the IFRS Foundation
Consolidated on 31 January 2022.
- Financial Stability BoardFSB publishes annual progress report on climate-related disclosures (12 October 2023)
The TCFD’s final task; the TCFD disbanded.
- IFRS FoundationUse of IFRS Sustainability Disclosure Standards by jurisdiction
Jurisdiction profiles (finalised approaches) and snapshots (preliminary).
- IFRS FoundationJurisdictional readiness assessment guide and tool (24 February 2026)
Nearly 40 jurisdictions taking steps; requirements in effect in 19.
- Department for Business and TradeUK SRS S1 and UK SRS S2 (25 February 2026)
The UK-endorsed versions of IFRS S1 and S2.
- Department for Business and TradeExposure drafts of UK SRS: consultation response, Annex A
The paragraph-by-paragraph difference map; UK SRS S2 based on IFRS S2 as amended in December 2025.
- Department for Business and TradeFramework for developing UK Sustainability Reporting Standards
The endorsement process and its two committees.
- Financial Reporting CouncilSustainability reporting developments: FAQs
New or amended ISSB standards need UK endorsement before they apply.
- Financial Conduct AuthorityPS26/19: Aligning listed issuers’ sustainability disclosures with international standards
Comply or explain against UK SRS, periods from 1 January 2027.
Continue reading
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UK SRS vs IFRS S1 and S2
Every key IFRS S2 paragraph and what UK SRS S2 changes, mapped to Annex A.
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TCFD vs UK SRS
How the TCFD’s pillars carry into the UK standards.
Who must comply with UK SRS
The FCA’s final rules and who sits outside them.