ESOS & SECR: the compliance engine room
Before UK SRS makes headlines, two workhorse regimes decide what most large UK organisations actually measure: ESOS energy audits and SECR annual disclosures.
Phase 4 qualification is tested this December — and the 2026 SECR review has put reform on the table.
This hub tracks both.
Why we cover these two regimes as one system
ESOS and SECR are usually treated as separate compliance chores owned by different teams — energy management on one side, financial reporting on the other.
That framing is increasingly obsolete.
ESOS, established by the 2014 Regulations[1], forces a four-yearly audit of where energy is actually consumed across buildings, transport and industrial processes[2].
SECR, created by the 2018 Regulations[3], forces an annual public disclosure of energy use and emissions in the directors’ report[5].
One generates the measurement infrastructure; the other publishes its outputs.
The arrival of UK SRS S2 completes the system: climate disclosures under the new standards demand exactly the energy and emissions data these two regimes already compel large organisations to produce[7].
The organisations handling this well are running one data pipeline with three outputs — ESOS notification, SECR disclosure, S2 metrics — rather than three projects.
Our analysis across this hub starts from that premise.
ESOS vs SECR vs UK SRS S2 — obligations compared
| ESOS (Phase 4) | SECR | UK SRS S2 | |
|---|---|---|---|
| Nature | Energy audit & notification | Annual public disclosure | Annual public disclosure (voluntary; FCA rules proposed) |
| Who | 250+ employees OR >£44m turnover and >£38m balance sheet | Quoted companies; unquoted companies & LLPs meeting 2 of: £36m / £18m / 250 | Voluntary now; listed companies proposed from FY2027 |
| Routes | ESOS energy audit, or ISO 50001 over total or significant consumption — DECs and GDAs removed by SI 2026/701 reg 26 | n/a | n/a |
| Cadence | Every 4 years, then an action plan and three progress updates | Every financial year | Every financial year |
| Deadline | 5 December 2027 (Phase 4); action plan 5 December 2028; updates 5 Dec 2029, 2030, 2031 | With annual report filing | With annual report (proposed) |
| Regulator | Environment Agency (UK scheme administrator); NRW, NIEA, SEPA and DESNZ by registered office | Conduct: FRC / Companies House filing | FCA (listed); DBT policy |
| Penalty exposure | Up to £50,000 + £500 per working day (80-day cap) + publication; no penalty for a missed action plan or progress update | No SECR-specific penalty; the operative offence is approving a non-compliant directors’ report (CA 2006 s.419(3)–(4)) | Listing Rule enforcement (once made) |
Energy & carbon compliance analysis on SRS Report
ESOS & SECR — frequently asked questions
What is the difference between ESOS and SECR?
ESOS is an energy audit scheme: qualifying organisations must assess their energy use every four years and notify the Environment Agency — it is about identifying savings, not public disclosure. SECR is an annual disclosure regime: in-scope companies must publish energy use, emissions and an intensity ratio in their annual report filed at Companies House. Many large organisations are caught by both.
When is the ESOS Phase 4 deadline?
The compliance notification deadline is 5 December 2027. Whether an organisation qualifies is tested on 31 December 2026 — any UK undertaking with 250 or more employees, or with an annual turnover over £44m together with an annual balance sheet total over £38m, on that date is in scope for Phase 4. The action plan then follows by 5 December 2028, with progress updates on 5 December 2029, 2030 and 2031.
Do the new 2025 company size thresholds change who reports under SECR?
No. The Companies Act size thresholds rose by around 50% for financial years beginning on or after 6 April 2025 (large: >£54m turnover, >£27m balance sheet), but SECR was unaffected — not by a saving provision, but because SECR’s own threshold table (SI 2008/410 Sch 7 para 20B) has always been self-contained and never cross-referred to the Companies Act sections that were amended. It still requires exceeding two of £36m turnover, £18m balance sheet, 250 employees. Companies reclassified as medium-sized under the new thresholds can still owe SECR disclosures.
How do ESOS and SECR relate to UK SRS?
They are upstream data sources. ESOS audits generate energy-consumption data and savings opportunities; SECR processes generate audited annual energy and emissions figures. Both map directly onto the metrics UK SRS S2 requires. Organisations that treat ESOS Phase 4 and SECR as a data-infrastructure project, rather than isolated filings, are effectively pre-building their S2 disclosure capability.
For the standards this data ultimately feeds, see the UK SRS Intelligence Hub. For the broader disclosure landscape including TCFD and ESG frameworks, see ESG reporting requirements in the UK.
- The Energy Savings Opportunity Scheme Regulations 2014 (SI 2014/1643), as amended 2023 — legislation.gov.uk
- Comply with the Energy Savings Opportunity Scheme (ESOS) phase 4 — Environment Agency, GOV.UK · Published 30 July 2026 — qualification 31 Dec 2026, compliance deadline 5 Dec 2027, action plan 5 Dec 2028
- The Companies (Directors’ Report) and LLPs (Energy and Carbon Report) Regulations 2018 (SI 2018/1155) — legislation.gov.uk · The SECR regulations
- 2026 post-implementation review of the SECR Regulations 2018 — Department for Energy Security and Net Zero, GOV.UK
- Environmental Reporting Guidelines: including SECR guidance — GOV.UK
- The Companies (Accounts and Reports) (Amendment and Transitional Provision) Regulations 2024 — legislation.gov.uk · Company size thresholds raised ~50% for FY beginning on/after 6 April 2025; SECR’s own, self-contained threshold table (SI 2008/410 Sch 7 para 20B) never cross-referred to these sections, so it was untouched
- UK Sustainability Reporting Standards (UK SRS S1 and S2) — Department for Business and Trade, GOV.UK · Published 25 February 2026