Energy Savings Opportunity Scheme (ESOS) compliance

What is ESOS?

The Energy Savings Opportunity Scheme is the UK’s mandatory energy assessment scheme for large organisations. Qualifying businesses must assess energy use across buildings, transport and industrial operations every four years, identify cost-effective efficiency opportunities, and report on implementation progress.

Turn ESOS Phase 4 into a commercial opportunity

The compliance window for ESOS Phase 4 is open and you can start preparing now, ahead of the 5th December 2027 deadline.

Organisations that engage early with ESOS are much more likely to unlock commercial value from the process. Concept can help you move beyond compliance – using ESOS to shape longer-term energy management and achieve tangible cost savings.

Speak to an ESOS Lead Assessor

Do I qualify for ESOS Phase 4?

Your organisation qualifies for ESOS Phase 4 if it operates in the UK and meets the following criteria:

Employs 250 or more people
Has an annual turnover exceeding £44 million
Has an annual balance sheet total exceeding £38 million

Not sure if you qualify? Get in touch for advice.

ESOS key deadlines

2nd Action Plan Progress Update (Phase 3): 5 December 2026
Qualification Date for Phase 4: 31 December 2026
Phase 4 Compliance Deadline: 5 December 2027
Phase 4 Action Plan Deadline: 5 December 2028
Phase 4 Progress Update Deadlines: 5 December 2029, 2030 and 2031

Read our guide to ESOS Phase 4

ESOS ACTION PLAN GUIDE

Download your free best practice guide now to unlock the full potential of your ESOS Action Plan and drive meaningful change in your organisation’s energy management.

Download Now

Why Concept?

Concept was established in 2008, to help organisations make better energy decisions. Our Environment Agency-approved ESOS Lead Assessors have been helping organisations achieve compliance since the scheme launched in 2014.

ESOS shouldn’t be onerous. We’ll help you streamline your approach to compliance and use your ESOS findings as a springboard for action. Our decarbonisation consultants will work with you to develop a strategy that delivers long-term cost and carbon savings. Get in touch today.

How we can help

ESOS Phase 4 compliance support - including data collection, energy audits & assessments, Lead Assessor sign off and reporting
ESOS Action Plan Progress Update support ahead of 5 December 2026 deadline
Offset compliance costs by implementing the energy savings
Achieve late ESOS Phase 3 compliance and minimise the penalty costs
Gain ISO 50001 as a route to ESOS compliance
Environment Agency audit support

GET IN TOUCH

Make ESOS Phase 4 count.

Feel free to contact one of our ESOS Lead Assessors who can advise on your ESOS Phase 4 obligations, as well as how to streamline the process and unlock long-term commercial benefits.