Energy Savings Opportunity Scheme (ESOS)

Energy Savings Opportunity Scheme (ESOS) Phase 4 – Key Information

The Energy Savings Opportunity Scheme (ESOS) is aimed at increasing energy efficiency to improve business profits and competitiveness as well as mitigating climate change.

The government scheme is aimed at large businesses and requires the submission of an ESOS report every 4 years, outlining energy saving opportunities. Some submissions will be audited by the Environment Agency to ensure compliance.

Do you qualify?

  • Do you employ 250 or more people?
  • Do you have an annual turnover in excess of £44 million, and an annual balance sheet total in excess of £38 million?
  • Are you part of a group where one entity meets the above criteria?

If the answer is yes to any of the above, then you are likely to qualify for ESOS, but contact us to explore further.

Phase 3 & New Requirements

Towards the end of ESOS Phase 3, new requirements were introduced:

  • A new Action Plan outlining efficiency measures – due 05/03/25.
  • An Annual Progress Report outlining what has been achieved in the 12-month period – due 05/12/25 and 05/12/26.

Due to these changes the Phase 3 Compliance date (when the ESOS report was due) was extended to 05/08/24.

Phase 4 Key Dates

  • Compliance date – 05/12/27
  • Action Plan due – 05/12/28
  • Annual Progress Reports – 05/12/29 and 05/12/30

Phase 4 is expected to introduce new inclusion criteria and align more closely with the UK’s Net Zero 2050 goals, increasing reporting requirements and commitments.

Although these dates may seem distant, planning in advance and starting work on ESOS, securing a good Lead Assessor early, is advisable.

How Can Indigo Swan Help?

To comply with ESOS, businesses must provide evidence of energy efficiency assessments during audits. Indigo Swan can:

  • Connect you with a qualified Lead Assessor to oversee the process and sign off the ESOS report.
  • Provide guidance on the new Action Plan and Annual Progress Reports (which require director sign-off but benefit from an assessor’s input).

Next Steps for Phase 4 Compliance

  1. Confirm eligibility – Compliance is assessed based on 31/12/26 criteria (ISO 50001 exemptions may change).
  1. Appoint a Lead Assessor – Find one via Energy Savings Opportunity Scheme (ESOS) – GOV.UK or contact Indigo Swan.
  1. Conduct energy audits – Analyse 12 months of energy use (including December 2026) and identify efficiency improvements.
  2. Submit the ESOS report to the Environment Agency by 05/12/27.
  3. Submit the Action Plan by 05/12/28 and Annual Progress Reports by the required deadlines.

Penalties for Non-Compliance

Failure to comply can result in fines and daily penalties, public disclosure of non-compliance, and potential reputational damage.

For full ESOS guidance, visit: Energy Savings Opportunity Scheme (ESOS) – Energy Savings Opportunity Scheme (ESOS) – GOV.UK

Or contact: hello@indigoswan.co.uk or esos@environment-agency.gov.uk

Book a free consultation today