ESOS Phase 3 – Latest Update

The legislation for ESOS Phase 3 compliance has been finalised and a newsletter has been issued confirming the changes.

Below we have summarised the changes shared in the newsletter for ESOS Phase 3.

Key Dates:

  • 5th June 2024 – compliance deadline for Phase 3 reporting (previously 5th December 2023).
  • 5th December 2024 – submission of energy efficiency action plan.
  • 5th December 2025 – update action plan to identify progress.
  • 5th December 2026 – update action plan to identify progress.

Other important changes to the legislation include the requirement to audit at least 95% of total energy consumption (previously 90%) and the requirement that all ESOS participants must produce an ESOS report. This includes those using alternative compliance routes such as ISO 50001 energy management system. Also, participants whose total energy consumption is less than 40 000 kWh no longer have to appoint a lead assessor. Instead, their compliance notification must be signed off by two directors.

As well as the above, in ESOS Phase 3, participants must:

  • Explain the appropriateness of the energy intensity ratios used.
  • Ensure site visits are representative of total energy consumption.
  • Notify the scheme administrator of anything relating to the participant’s energy consumption and ability to comply.
  • Disclose all relevant information from the ESOS report and alternative compliance routes to all members of the corporate group.
  • Disclose all action plans, progress updates and other notifiable information to the public.
  • Clearly detail the responsibilities for the action plan and subsequent progress updates should there be a change in personnel.
  • Clearly detail the methodology used if estimates are used to calculate energy consumption.


ESOS is an energy auditing and assessment scheme introduced by the UK government, intended to encourage larger organisations to focus on being more energy efficient. It is a mandatory scheme for any UK company that either employs 250 or more employees; or has an annual turnover of £44 million or more and an annual balance sheet total more than £38 million. We are currently in ESOS Phase 3.

For information about how the Swan Energy team can support you with ESOS Phase 3, click here.

Rebecca Scarratt

Carbon Consultant

Rebecca Scarratt

Carbon Consultant

Rebecca has joined the Swan Energy team in 2021. She graduated from the University of Hull with a BSc in Geology with Physical Geography in 2020 and went on to do a MSc in Renewable Energy. Her Masters’ thesis focused on how future climate change may impact the Humber region’s wind energy sector and how adaptation strategies could be used to reduce vulnerability.

In her role at Swan Energy, Rebecca supports the consultancy work the team does with clients across the UK.