Energy Savings Opportunity Scheme (ESOS)

The government’s Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment for larger organisations in the UK that meet the qualification criteria. The scheme ensures that organisations conduct energy audits across key buildings and operations every four years to identify ways to become more energy efficient.

ESOS is mandatory for all UK organisations that meet at least one of the following criteria:

They employ 250 people or more
They have an annual turnover of more than £44 million and an annual balance sheet total of more than £38 million
They are an overseas company with a UK-registered establishment that has 250 or more UK employees (paying income tax in the UK)

If your organisation is part of a group where any of the companies meet the above criteria, all organisations in the group must comply with ESOS.

How does my organisation comply with ESOS?

To comply with the Energy Savings Opportunity Scheme (ESOS), your organisation must carry out energy audits every four years, verified and approved by a certified Lead Energy Assessor. These audits evaluate the energy intensity ratio and track energy consumption trends across your key buildings and operations. Achieving compliance involves collecting accurate energy data, conducting comprehensive assessments, and keeping records of the results

1. Energy Audits and Reporting

Conduct energy audits with a qualified Lead Energy Assessor, who will review your energy usage and prepare an ESOS report. This report must be signed off and declared to the Environment Agency via the MESOS platform.

2. Action Plan Submission

Use the MESOS system to submit your Action Plan by March 5th, 2025. Ensure your plan includes steps to reduce energy consumption, timelines, and projected savings.

Please note: the Department for Energy Security and Net Zero (DESNZ) has decided not to allow ESOS participants to add restricted users (external lead assessors) to their MESOS accounts for creating action plans. Find out more in our blog.

3. Annual Progress Reports

After submitting your Action Plan, you must provide progress updates by December 5^th, 2025, and December 5^th, 2026. These updates should include energy-saving actions completed and their estimated savings.

The Energy Savings Opportunity Scheme (ESOS) – Phase 3 Deadlines

How can our ESOS experts help your organisation?

Our team provides comprehensive support to guide your organisation through every step of ESOS compliance:

1. Qualification Assessment

We’ll determine whether your business qualifies for ESOS and explain your obligations.

2. Data Collection & Metrics

We gather 12 months of energy data and calculate key ESOS metrics, including energy intensity ratios and carbon emissions.

3. Energy Audits

Our Lead Energy Assessors conduct energy audits, identifying cost-effective energy-saving opportunities. The audit results are compiled in a report, signed off by our Lead Assessor.

4. ESOS Reporting & Compliance

We prepare and submit your ESOS compliance documentation via the MESOS platform, keeping your account up to date.

5. Action Plan Submission

For ESOS Phase 3, we assist in creating and submitting your Action Plan by March 5, 2025, detailing steps to reduce energy consumption and projected savings.

6. Annual Progress Reports

We’ll help you submit the required progress updates by December 5, 2025, and December 5, 2026, ensuring compliance with ongoing reporting.

7. Evidence Pack & Ongoing Support

We provide a full ESOS evidence pack and ongoing support, ensuring all documentation is ready for audits.