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Section · Energy audits
ESOS Phase 4
The Energy Savings Opportunity Scheme — mandatory energy audits for large UK organisations. Phase 4 qualification, the December 2027 deadline, and how ESOS sits alongside SECR and UK SRS.
Live deadline · ESOS Phase 4
5 December 2027
—days until the Phase 4 deadline
Qualifying organisations must complete energy audits and notify by this date. See ESOS Phase 4
Start here
All guides →How-to
ESOS, step by step
Guide · 12 min
ESOS compliance obligations
The full walkthrough: qualification, audits, action plan and notification.
Deadline
Phase 4 deadline
Guide · 8 min
ESOS Phase 4 — 5 Dec 2027
The deadline, the assessment period, and the four-year cycle.
Scope
Qualification criteria
Guide · 9 min
ESOS Phase 4 qualification
250+ employees OR £44m turnover and £38m balance sheet.
Compare
ESOS vs SECR
Guide · 7 min
ESOS vs SECR
Different thresholds, different obligations — how they interact.
Most read
This month →Key updates
All updates →- 5 Dec 2027
- 31 Dec 2026
- Cycle
- Compare
ESOS phases
Full timeline →Tool
Does ESOS apply to you?
Check your group against the employee and financial tests to see whether ESOS Phase 4 applies — and what to do by 5 December 2027.
Run the compliance checkRelated sections
All sections →Energy & carbon
SECR
Streamlined Energy & Carbon Reporting — the disclosure regime that sits alongside ESOS audits.
Standards
UK SRS
The UK sustainability reporting regime ESOS energy data increasingly feeds.
Software
Carbon reporting software
Platforms that turn ESOS energy data into SECR and UK SRS outputs.
Advisory
Consultancy
Energy and carbon consultancies that deliver ESOS audits.
About ESOS
The Energy Savings Opportunity Scheme operates under the Energy Savings Opportunity Scheme Regulations 2014 and is administered by the Environment Agency.
Phase 4 qualification is assessed at 31 December 2026, with a compliance deadline of 5 December 2027.
Authority sources
02
Environment Agency / GOV.UK
03
legislation.gov.uk