ESOS

ESOS Compliance: A Practical Guide for UK Businesses

ESOS (Energy Savings Opportunity Scheme) is a UK government initiative that requires large organisations to carry out regular energy assessments and identify opportunities to improve energy efficiency. If your organisation qualifies, you must complete an energy audit and notify the Environment Agency — or face enforcement action.

This guide explains who needs to comply, what’s required, and how Zeropath can help make the process easier.

What is ESOS?


ESOS is a mandatory energy reporting and audit scheme for large UK businesses, run in compliance phases. It aims to help organisations cut energy use, lower costs, and support the UK’s Net Zero targets.

We are now in Phase 3, with a compliance deadline of:

🗓️ 6 August 2024

Organisations must collect data, complete assessments, and submit a notification of compliance by this date.

Who Needs to Comply?


Your organisation is required to comply with ESOS if, on the qualification date (31 December 2022), it either:

  • Employs 250 or more people, OR
  • Has an annual turnover of more than £44 million and an annual balance sheet total over £38 million

If your organisation is part of a group, ESOS may apply to the entire UK group if any one member meets the criteria.

For more detailed eligibility rules, see GOV.UK’s ESOS guidance.

What Does ESOS Require?


To comply with ESOS Phase 3, your organisation must:

1. Measure Total Energy Consumption

Across buildings, industrial processes, and transport.

2. Conduct an Energy Audit

Or use an alternative route to compliance, such as:

  • A valid ISO 50001 certification (for the whole organisation)
  • Display Energy Certificates (DECs)
  • Green Deal Assessments

3. Identify Energy Efficiency Opportunities

The audit must highlight realistic ways to reduce energy use and cut costs.

4. Appoint a Lead Assessor

You must appoint a registered ESOS Lead Assessor to carry out or review your audit.

5. Submit a Notification of Compliance

You must report to the Environment Agency using the official online portal.

What’s New in Phase 3?


The UK government has introduced improvements to ESOS in Phase 3, including:

  • Mandatory energy intensity metrics
  • Clearer reporting on post-audit actions
  • Enhanced data quality standards
  • Stricter expectations for audit detail and evidence

These changes are designed to increase the impact of ESOS and ensure it contributes meaningfully to the UK’s climate goals.

How Zeropath Can Help


At Zeropath, we simplify ESOS compliance by helping you:

  • Collect and consolidate energy data across your operations
  • Prepare or support energy audits in partnership with approved Lead Assessors
  • Identify emissions and energy savings across Scopes 1 and 2
  • Generate a compliant ESOS report aligned with Phase 3 requirements
  • Maintain an audit trail for evidence and verification

We also help integrate your ESOS outputs with your SECR, CRP, and Net Zero strategies — so you can stay compliant and aligned across frameworks.

Common Pitfalls to Avoid


  • Missing the deadline: Non-compliance can lead to enforcement and financial penalties.
  • Incomplete audits: You must cover at least 90% of your total energy consumption.
  • Failing to use a Lead Assessor: This is mandatory unless you’re using ISO 50001.
  • Poor follow-up: Phase 3 requires clearer reporting on action taken after the audit.

Useful Resources

  • Official ESOS Guidance (GOV.UK)
  • Notification Portal
  • ESOS Compliance Handbook (PDF)

Need Support?

Navigating ESOS doesn’t have to be difficult.

Get in touch and let us show you how simple it can be to stay compliant — and make meaningful energy savings in the process.