Energy Savings Opportunity Scheme (ESOS) – 7th August 2026
The government has made changes to ESOS, which came into force on 22nd July 2026 via the Energy Savings Opportunity Scheme (Amendment) Regulations 2026.
The main changes are:
- Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as compliance routes.
- Progress against action plan commitments in Phase 3 to be included in the ESOS assessment.
- Where action plan commitments have not been met, participants must provide an explanation.
Organisations which meet the qualification criteria on the qualification date for the fourth compliance period of ESOS, 31st December 2026, are required to comply with ESOS and these changes by 5th December 2027. The ESOS guidance explaining how to comply has been updated to reflect the changes.
Removal of DECs and GDAs as Compliance Routes
These compliance routes have been removed as they are no longer considered to meet best practice standards. This means that from Phase 4 ESOS participants must use only energy audit(s) and / or ISO 50001 certification as compliance routes.
Progress Against Action Plan Commitments
To meet this requirement, participants must provide additional details about the energy savings achieved during the compliance period. The details, which must be included in the ESOS report and notification of compliance (NOC) and which will not be published, are:
- A description of each measure implemented to achieve the energy savings
- Energy savings achieved by each measure
- Energy saving category of each measure
Action Plan Review
If you were eligible to comply with ESOS in Phase 3, you were required to prepare and submit an action plan. You are now required to review your action plan as part of the ESOS assessment and the information provided in the ESOS report and NOC. The details required, which will not be published, are:
- Any measures proposed in the action plan and not implemented
- Reasons why the measures were not implemented.
Additional Phase 4 Changes
Lead assessors are now required to notify their professional body of each ESOS assessment they complete/review, along with the ESOS participant’s contact details. This is to allow the professional body to seek the ESOS participant’s consent to share its ESOS report so the professional body can carry out a quality check.
The notification of compliance (NOC) must now include the following:
- Total number of sites covered by energy audit(s)
- ISO 50001 certification details
- UK SIC codes only (replacing international codes in Phase 3)
- Recording of methods and data used for calculations
MESOS User Management
Organisations should regularly review and maintain their contacts within the MESOS reporting system to ensure information remains accurate and up to date. Removing outdated contacts, such as individuals who have changed roles or left the organisation, helps protect sensitive information, prevents missed communications, and reduces the risk of unauthorised access.
