ESG standards: what binds in the UK

ESG standards are published documents that set specific requirements for measuring, reporting, assuring or managing environmental, social and governance matters, specific enough that a company can comply with them.

They range from disclosure standards such as UK SRS and the GRI Standards, to measurement standards such as the GHG Protocol, to assurance standards such as ISSA (UK) 5000 and management system standards such as ISO 14001.

For disclosure: UK SRS S1 and S2, the Companies Act climate disclosures, SECR and the FCA’s listing rules.

For measurement: the GHG Protocol and the government’s conversion factors.

For assurance: ISSA (UK) 5000 and ISAE (UK) 3000.

For governance: the UK Corporate Governance Code.

For conduct: the FCA’s anti-greenwashing rule.

Only some of these bind, and each binds a different set of organisations.

SECR, the Companies Act climate disclosures, the section 172(1) statement, the Modern Slavery Act statement and gender pay gap reporting are law for the organisations each reaches.

The FCA’s anti-greenwashing rule binds every authorised firm.

UK SRS is voluntary, except that listed companies in five categories must report against it or explain from accounting periods beginning on or after 1 January 2027.

ISSA (UK) 5000, ISO 14001 and the GRI Standards are voluntary.

A standard sets requirements precise enough that a report or a system can be said to comply with it, such as UK SRS S2 or ISO 14001.

A framework gives principles and a structure without a compliance test of its own, such as the TCFD’s four recommendations.

Standards are what regulators point to; frameworks are what standards are often built on.

UK SRS S1 and S2 are standards: specific disclosure requirements published by the Department for Business and Trade on 25 February 2026, built on the ISSB’s IFRS S1 and S2.

They are voluntary in themselves, and the FCA’s PS26/19 makes reporting against them, or explaining why not, a listing rule for five categories of listed company.

There is no single ISO ESG standard.

The ISO standards most used in ESG reporting are ISO 14001 (environmental management systems, now in its 2026 edition), ISO 50001 (energy management), ISO 45001 (occupational health and safety), the ISO 14064 family for greenhouse gas quantification and verification, and ISO 14068 on carbon neutrality, whose 2023 first part was withdrawn on 11 September 2026.

All are voluntary.

The Companies (Strategic Report) (Climate-related Financial Disclosure) Regulations 2022, SI 2022/31, which apply for financial years beginning on or after 6 April 2022.

They amended the Companies Act 2006 to require eight climate-related disclosures in the strategic report from the categories of company in section 414CA with more than 500 employees.

From 29 June 2028, the FCA.

The Financial Services and Markets Act 2000 (Regulated Activities) (ESG Ratings) Order 2025, made on 15 December 2025, brings the provision of certain ESG ratings into the FCA’s perimeter.

It regulates the firms that provide ratings, not the companies they rate.

The FCA’s UK SRS listing rules do not require a company to commission assurance.

Separate overseas or contractual requirements may apply.

ISSA (UK) 5000, issued by the FRC on 12 November 2025, is effective for engagements on periods beginning on or after 15 December 2026 and is for voluntary use.

Under the FCA’s final rules, a listed company states whether it obtained assurance and, if so, from whom, over what, to what level and on which standard; obtaining it is not required.