ESOS Phase 4 Explained

ESOS Phase 4 is a mandatory energy assessment scheme for large UK organisations. If your business qualifies, you must complete an ESOS audit or risk fines of up to £50,000. This guide explains what ESOS Phase 4 is, who qualifies, and what you need to do next.

What is ESOS?

The Energy Savings Opportunity Scheme (ESOS) is a UK government regulation that requires large organisations to assess their energy use and identify efficiency opportunities. It runs in 4-year phases, and Phase 4 is the current compliance period.

Who Qualifies for ESOS?

You must comply if your organisation is considered a “large undertaking”.

• 250 or more employees

• OR fewer employees but turnover over £44 million AND a balance sheet over £38 million

• Part of a larger corporate group that meets these criteria

What is the ESOS Phase 4 Deadline?

The ESOS Phase 4 compliance deadline is expected in 2027, with a qualification date in 2026. However, businesses should start preparing early, as collecting data and completing audits can take time.

What Happens if You Don’t Comply?

Failure to comply with ESOS can result in serious penalties.

• Fines of up to £50,000

• Additional daily penalties

• Public naming by the regulator

What Do You Need to Do for ESOS Compliance?

1. Measure your total energy consumption

2. Conduct energy audits (covering at least 95% of energy use)

3. Identify energy-saving opportunities

4. Get sign-off from a certified ESOS Lead Assessor

5. Submit your compliance notification

How We Can Help?

We provide a complete ESOS compliance service to make the process simple and stress-free.

• ESOS qualification checks

• Data collection support

• Site energy audits

• Lead assessor sign-off

• Full compliance reporting

Need help with ESOS compliance? Book a free consultation today and get clarity on your obligations.