The main ESOS assessment must be completed once every four years. However, ESOS also includes reporting requirements between each four-year assessment.
After completing an ESOS assessment and submitting the notification of compliance, qualifying organisations must submit an Action Plan setting out the energy-saving measures they intend to take. This is followed by annual Progress Updates reporting what has been implemented and the estimated energy savings achieved.
For Phase 3, the final Progress Update is due on 5 December 2026. The next full ESOS assessment is Phase 4, with the compliance deadline on 5 December 2027.
Keeping accurate energy and project records throughout the compliance cycle can make both the Progress Updates and the next ESOS assessment easier to complete.
