Guidance

Appendices A1 and A2: Report checklists for participants

Updated 14 August 2025

Summary of section 10 guidance on requirements for the ESOS report.  You must refer to the specific subsections below for full details.  

All organisations that qualify for ESOS (see section 1.1) must complete an ESOS report unless they have zero energy supplies.

Section ref: 10.1.1 - Details of the responsible undertaking and individuals

You must include:  

• name of responsible undertaking
• director(s) or equivalent (for example, responsible officer(s)) name and full title or position in the participant
• where recorded, names of personnel who have contributed at least 5% of the total time spent on site visits, data collection or drafting of ESOS report

Section ref: 10.1.2 - Relevant undertakings (if applicable)

You must include:

• the number of relevant undertakings comprising the participant
• corporate group structure chart (example below) or other information setting out the relationship between the undertakings

Written explanation of flowchart for accessibility:

A Global Ltd is the Global parent overseeing all entities. Under A Global Ltd is A Export Ltd (disaggregated), A UK Ltd (Responsible undertaking) and A Holdings Ltd.

Under A Holdings Ltd is Trust Asset AA.

Under A UK Ltd (Responsible undertaking) is A Retail Ltd, A Manufacturing Ltd and A Logistics Ltd.

Under A Retail Ltd is Franchise A1 and Franchise A2.

Under A Manufacturing Ltd is A Packaging Ltd (Sold March 2023).

Under A Logistics Ltd is A Freight Ltd and A Deliveries Ltd.

Section ref: 10.1.3 - Lead assessor details (where required to be appointed)

You must include: 

• the name of the lead assessor
• the name of the approved register listing the lead assessor

Section ref: 10.1.4 - Calculations relating to the ESOS assessment

You must include:

• total energy consumption in kWh
• significant energy consumption in kWh (if applicable)
• percentage of total energy consumption which the significant energy consumption represents (if applicable)
• energy intensity ratios for each organisational purpose

Section ref: 10.1.5 - Details of energy saving opportunities (from audits) and energy saving measures (from alternative compliance routes)

Include information obtained through energy audits where reasonably practicable, or through alternative compliance routes where available:

• any way for the participant to improve its energy efficiency through recommended energy saving opportunities / measures
• for each energy saving opportunity / measure, the organisational purpose and energy saving category to which it most closely relates
• any considerations relevant to its implementation of the energy saving opportunity/measure,  including, where applicable obligations under part 3 of Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015 in relation to buildings where the ESOS participant is a landlord or tenant
• schemes under which grants or public funds could support implementation of each energy saving opportunity/measure, if applicable
• estimate of the annual reduction in energy spend and the annual reduction in energy consumption which would be achieved as a result of implementing each energy saving opportunity / measure
• a recommended programme, including a timescale, for implementing the energy saving opportunities / measures

Section ref: 10.1.6 - Estimates of the potential annual reduction in energy spend and energy consumption from implementing energy saving opportunities and measures

Include information obtained through energy audits, or through alternative compliance routes where such information is available. This should cover the following in both pounds sterling and energy units for all energy audits and alternative compliance routes used:

• the total potential annual reduction in energy spend and energy consumption from carrying out all energy saving opportunities / measures
• the potential annual reduction in energy spend and energy consumption for carrying out energy saving opportunities / measures, broken down by organisational purpose
• the potential annual reduction in energy spend and energy consumption for carrying out energy saving opportunities / measures, broken down by energy saving category

Section ref: 10.2 - Additional requirements for participants complying using an energy audit

For each energy audit carried out, you must include:

• date or period over which the energy audit was carried out
• 12-month period to which the energy audit relates
• energy consumption relating to, as applicable, areas of significant energy consumption or total energy consumption, calculated for the purpose of the audit
• total number of sites covered by the audit
• number of sites visited for the audit
• reasons why the sites visited for the energy audit are representative
• so far as reasonably practicable, a description of the analysis carried out of the participant’s energy consumption and energy efficiency

Where reasonably practicable through the energy audit, include the following information.

For each energy saving opportunity: 

• an estimate, in pounds sterling of the costs and benefits of implementing the energy saving opportunity
• any other non-financial costs and benefits of implementing the energy saving opportunity
• the payback period calculated for the energy saving opportunity

For the recommended programme for implementing the energy saving opportunities:

• estimated costs and benefits of implementing the programme
• the payback period calculated for the programme

Section ref: 10.3 - Additional requirements for participants complying using alternative compliance routes

You must include for each alternative compliance route used (ISO50001, DEC, GDA):

• which assets and activities are covered by the alternative compliance route (this must include information on where a building covered by a DEC or GDA uses energy that is not covered by the DEC or GDA)
• the percentage of the total energy consumption covered by each alternative compliance route

Section ref: 10.4 - Estimating energy savings since the previous ESOS assessment 

You must include:

• an estimate of energy savings achieved in the compliance period (from immediately after the previous compliance date up to the current compliance date)

Where reasonably practicable, include:

• the measures implemented to achieve the energy savings in the compliance period

Section ref: 10.4.1 - Categorising energy savings and calculating subtotals

You must include:

• estimates of the proportion of energy savings achieved in the compliance period that most closely relate to each organisational purpose
• for each measure identified as achieving energy savings in the compliance period, any energy saving category previously identified to which it most closely relates
• for each measure identified as achieving energy savings in the compliance period, any payback period previously calculated for the measure

Section ref: 10.5 - Sign-off of ESOS report

Confirmation must be provided in the online notification system (known as MESOS) that the director(s) or equivalents (for example, responsible officer(s)) have seen and considered recommendations (energy saving opportunities and measures) of the audit / any alternative routes to compliance and that the ESOS report includes all information required by the ESOS Regulations.