Master Roadmap
The UK sustainability regulation timeline
UK sustainability reporting isn't one rule with one deadline — it's a decade-long build-out of overlapping regimes, now converging on UK SRS.
This timeline maps every key milestone from ESOS (2014) to mandatory nature reporting (likely 2027+).
UK sustainability reporting isn't one rule with one deadline — it's a decade-long build-out of overlapping regimes, now converging on the UK Sustainability Reporting Standards (UK SRS) 1. This timeline pulls every key date into one place: the regimes already in force, what is happening in 2026, and the deadlines still ahead.
The foundations (2014–2023)
The architecture began well before UK SRS. The Energy Savings Opportunity Scheme (ESOS) has required large organisations to audit their energy use on four-year cycles since 2014 44. The Task Force on Climate-related Financial Disclosures (TCFD) was created in 2015 and gave climate reporting its lasting four-pillar structure 36. Streamlined Energy and Carbon Reporting (SECR) brought mandatory energy and carbon disclosure into annual reports from 2019 10. Then in June 2023 the ISSB published IFRS S1 and S2 — the global baseline UK SRS is built on — and the TCFD was disbanded, its work absorbed into the ISSB 3812.
The build-out (2024–2025)
The pace picked up sharply. The FCA's anti-greenwashing rule took effect on 31 May 2024, with sustainable investment labels following in July 2024 and naming-and-marketing rules from 2 December 2024 48. In June 2025 the Government launched a package of consultations — on the UK SRS exposure drafts, on assurance, and (via DESNZ) on transition plan requirements 18. In July 2025 HM Treasury decided not to proceed with a UK Green Taxonomy, confirming a disclosure-first path 17. The autumn brought the Modernising Corporate Reporting programme 24 and the opening of the GHG Protocol's Scope 2 revision consultation 34. December 2025 saw the next SDR disclosure tiers take effect and the ESG Ratings Order signed into law 4847.
Coming — 2027 and beyond
The mandatory era begins in 2027. The FCA proposes mandatory UK SRS S2 climate reporting for listed companies for accounting periods beginning on or after 1 January 2027 6. Scope 3 emissions follow on a comply-or-explain basis after a one-year relief, effectively from 2028, with the first reports published that year; wider UK SRS S1 disclosures follow after a two-year relief, effectively from 2029 827. Alongside: the GHG Protocol's revised standards are due by the end of 2027 34; the ESOS Phase 4 compliance deadline is 5 December 2027 44; UK ESG ratings providers must be FCA-authorised by 29 June 2028 47; and the Government is expected to consult on extending mandatory reporting to large private companies through the Modernising Corporate Reporting programme 24.
Converging on UK SRS
The through-line is consolidation onto UK SRS: a patchwork of energy, carbon and climate rules built up over a decade is being unified into a single ISSB-aligned standard, surrounded by supporting regimes for investment products (SDR), the ESG data market (ratings regulation), and transition planning.
Each milestone above links to its full guide.
When does UK SRS become mandatory?
The FCA proposes mandatory UK SRS S2 climate reporting for listed companies for accounting periods beginning on or after 1 January 2027, subject to Policy Statement confirmation expected autumn 2026.
If confirmed, Scope 3 emissions would move to comply-or-explain from 1 January 2028 after a one-year transitional relief, and UK SRS S1 (broader sustainability) is proposed on a comply-or-explain basis from 1 January 2029.
What's the timeline for Scope 3 and S1?
Under the FCA's CP26/5 proposal (subject to the autumn 2026 Policy Statement): Scope 3 emissions reporting would get one-year relief and shift to comply-or-explain from 1 January 2028, while UK SRS S1 general sustainability would get two-year relief on a comply-or-explain basis from 1 January 2029.
When is the FCA Policy Statement?
The FCA expects to publish its Policy Statement on the proposed mandatory UK SRS rules in autumn 2026, following the CP26/5 consultation that closed on 20 March 2026.
What are the ESOS Phase 4 dates?
ESOS Phase 4 runs from 6 December 2023 to 5 December 2027, with a qualification date of 31 December 2026 and compliance deadline of 5 December 2027.
This is the current four-year energy audit cycle.
When must ESG ratings providers be authorised?
In-scope ESG ratings providers must obtain FCA authorisation by 29 June 2028, following the ESG Ratings Order that was signed into law on 15 December 2025.
What's the deadline for transition plans?
There's no current deadline as transition plans aren't yet mandatory.
DESNZ consulted on making them mandatory in 2025 but the Government has kept its options open.
Currently, companies must disclose transition plans under UK SRS S2 only if they have one.
Related guides & references
UK SRS S2: Climate-Related Disclosures
The standard proposed mandatory for in-scope listed companies from 1 January 2027 under FCA CP26/5.
FCA SDR and Anti-Greenwashing
The FCA rules for sustainable investment products and asset managers.
SECR: UK Energy and Carbon Reporting
The foundational energy and carbon reporting regime from 2019.
Transition Plans Under UK SRS
Current requirements and the debate over making transition plans mandatory.
ESG Reporting in the UK
Complete picture of how all UK ESG reporting regimes connect.
UK Sustainability Reporting Guide
The umbrella guide to the entire UK sustainability reporting landscape.