Global Framework

The global standards behind UK SRS: ISSB, IFRS, ESRS and SASB

UK SRS operates within a global system of sustainability standards. Here's how the ISSB's IFRS S1 and S2, the EU's ESRS, and the SASB framework relate to each other — and where UK SRS sits in the international landscape.

IFRS S1 and S2 — the global baseline

IFRS S1 sets the general requirements for disclosing sustainability-related financial information; IFRS S2 applies that framework to climate 38. They took effect on 1 January 2024, but are not automatically mandatory anywhere — each country decides whether to endorse them, which is exactly what the UK did in creating UK SRS 38 15. Adoption is now broad: more than 30 jurisdictions, representing over half of global GDP, have adopted or are adopting the ISSB standards, some in full and some climate-only 39. *(For UK-specific detail, see the UK SRS S1 and UK SRS S2 guides.)*

ESRS and CSRD — the EU's parallel system

The European Sustainability Reporting Standards (ESRS), mandatory under the EU's Corporate Sustainability Reporting Directive (CSRD), are the EU's equivalent — but broader 26. The defining difference is materiality: ESRS use double materiality (both financial impact on the company and the company's impact on the world), whereas IFRS/UK SRS use financial materiality only 29. The two are not isolated: EFRAG aligned the ESRS financial-materiality definition with the ISSB and published interoperability guidance, with extensive overlap on climate, so companies caught by both can reuse much of the same data 31.

Where UK SRS fits

UK SRS is therefore the UK's node in an ISSB-aligned global network — deliberately kept close to the international baseline for comparability, while diverging from the EU's broader, double-materiality approach 2 29. The practical upshot: a UK company reports under UK SRS at home, may face ESRS in Europe, and benefits from the interoperability work designed to let one data set serve both 31.

What are IFRS S1 and S2?

IFRS S1 sets general requirements for sustainability-related financial disclosures, while IFRS S2 applies that framework specifically to climate. Published by the ISSB in June 2023, they form the global baseline for sustainability reporting, built on TCFD, SASB and integrated reporting frameworks.

How many countries use the ISSB standards?

More than 30 jurisdictions, representing over half of global GDP, have adopted or are adopting the ISSB standards. Some adopt the full suite (S1 and S2), others climate-only (S2). Each country decides whether to endorse them — which is exactly what the UK did in creating UK SRS.

What are the ESRS?

The European Sustainability Reporting Standards (ESRS) are the EU's sustainability standards, mandatory under the Corporate Sustainability Reporting Directive (CSRD). They're broader than ISSB standards because they use double materiality — reporting both financial impacts on the company and the company's impacts on the world.

What are SASB standards and are they still used?

SASB developed industry-specific sustainability metrics for 77 industries across 11 sectors. In 2022, the IFRS Foundation absorbed SASB, and the ISSB now maintains and enhances these standards. They feed directly into IFRS S1 and S2, though UK SRS makes their use permissive rather than mandatory.

How does UK SRS relate to IFRS S1 and S2?

UK SRS S1 and S2 are the UK's endorsed versions of IFRS S1 and S2, with six UK-specific amendments. They're not automatically mandatory — each country decides whether to endorse ISSB standards, which the UK did in creating UK SRS.

ESRS vs IFRS — what's the difference?

The key difference is materiality: ESRS use double materiality (financial impact plus impact on world), while IFRS/UK SRS use financial materiality only. However, EFRAG aligned the financial-materiality definitions and published interoperability guidance, so companies subject to both can often reuse the same data.