Become an EMA Registered ESOS Lead Assessor

How to become an EMA Registered ESOS Lead Assessor?

The four-step process through which a candidate is placed on the register is outlined below.

1. 1. 1. 1. Application — The application form can be downloaded here.
            NB. As part of the application each candidate must submit a CV, copies of academic, vocational or professional qualification certificates and evidence of competence in the mandatory areas outlined in PAS 51215:2014 and as outlined in the Competence and Commitment section of the application form. In addition to the application form, CV and certificates, the initial pack should also include a signed copy of the EMA Code of Conduct (this can be done within the application form).
            Applicants are expected to have a minimum of four years’ relevant professional experience in energy assessment and energy auditing. They should be able to demonstrate competence in carrying out basic energy assessments - including plant rooms - of typical types of energy equipment and systems, such as heating and hot water, cooling, pumping, air handling, lighting, compressed air and small power systems (e.g. IT and kitchen equipment). Applicants should be capable of conducting energy audits across a range of sites and sectors to identify straightforward opportunities for energy savings and carbon reduction.
         2. Become an ESOS Lead Assessor Course — This one day tutor-led virtual course (Zoom delivery) has been designed to ensure successful candidates are conversant in all aspects of ESOS. The next course will be delivered on 4 November 2026. NB. A place on the course is guaranteed only upon the EMA's review of the application pack, deemed all evidence satisfactory, reference checked and payment received.
         3. Written Assessment — Each candidate will be asked to complete a post-course written assessment to progress to the Peer Review Interview stage.
         4. Peer Review Interview — The candidate will then undergo a peer-review interview (conducted via Zoom) by two members of the EMA ESOS Scrutiny Panel to check the candidate's knowledge of the ESOS compliance requirements, knowledge gained through the process, professional energy management experience and technical skills gained throughout candidate's career, and also to check the validity of the evidence provided at the previous stages.

What is ESOS?

The Energy Savings Opportunity Scheme (ESOS), as an energy assessment and energy savings scheme, mandates that all large enterprises carry out an ESOS compliant energy assessment and identify energy efficiency opportunities at least ones every four years. ESOS was established through the Energy Savings Opportunity Scheme Regulations 2014 (ESOS Regulations) and significantly amended in 2023, through The Energy Savings Opportunity Scheme (Amendment) Regulations 2023, with additional amendments implemented in July 2026 through the Energy Savings Opportunity Scheme (Amendment) Regulations 2026.

Who has to comply with ESOS Phase 4?

An organisation must comply with Phase 4 if it qualifies on the qualification date of 31 December 2026.

1. Any UK organisation must comply with the Energy Saving Opportunities Scheme (ESOS) if it is a large undertaking, or is part of a corporate group which includes another UK undertaking, and meet either one or both of the conditions below:

– has 250 or more employees, or
– has a turnover of more than £44 million annually,  and an annual balance sheet total of more than £38 million

2. Any overseas (non-UK registered) company with a UK registered establishment which has 250 or more UK employees

The qualification assessment is based on the organisation’s status on 31 December 2026, and qualifying participants must complete their ESOS assessment and submit their Notification of Compliance (NOC) by 5 December 2027.

Organisations should assess qualification early, particularly where group structures, acquisitions or disposals may affect eligibility.

Key dates for Phase 4

The Phase 4 timeline, which started on 6 December 2023 is straightforward.

• 31 December 2026: Qualification date for Phase 4
• 5 December 2027: Deadline for Notification of Compliance

Although the compliance deadline falls in December 2027, organisations are encouraged to begin data collection and planning well in advance, especially where multiple sites or complex operational processes are involved.

The Comply with the Energy Savings Opportunity Scheme (ESOS) Phase 4 Guidance explains how to comply in Phase 4. You can check if your organisation qualifies here.

The EMA offers opportunities for your company to train one of your staff member to undertake your ESOS compliance, or to appoint one of the EMA Registered Lead Assessors. If you have any questions regarding the training to become a registered ESOS Lead Assessor or appointing an ESOS Lead Assessor, please email [email protected].

ESOS Phase 4 Changes

The Energy Savings Opportunity Scheme (ESOS) in its fourth compliance phase introduced a handful of amendments through the Energy Savings Opportunity Scheme (Amendment) Regulations 2026, which came into force on 22 July 2026. These changes strengthen the focus on demonstrating real energy savings, improving the quality of reporting and aligning ESOS with recognised best practice in energy management and savings.

The seven main changes in ESOS Phase 4

1. Display Energy Certificates and Green Deal Assessments have been removed

One of the most significant regulatory changes is the removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as recognised compliance routes.

In Phase 3, organisations could use DECs or GDAs to demonstrate compliance for certain buildings. From Phase 4, these routes are no longer considered consistent with current best practice. As a result, participants must now comply through:

• Energy audits, and/or
• ISO 50001 certified Energy Management Systems.

This change creates a more consistent approach across all qualifying organisations and reinforces the importance of comprehensive energy assessments.

2. New exemptions for ISO 50001 participants

Phase 4 also introduces important changes for organisations certified to ISO 50001.

Previously, exemption from appointing a Lead Assessor applied only where the ISO 50001 system covered the organisation’s Total Energy Consumption (TEC).

Under the new regulations, organisations with ISO 50001 certification covering either:

• Total Energy Consumption (TEC), or
• Significant Energy Consumption (SEC)

are exempt from both:

• appointing a Lead Assessor, and
• producing an ESOS Report.

This reduces administrative burden for organisations operating mature energy management systems while recognising the robustness of ISO 50001 certification.

3. Progress against Phase 3 action plans must now be reported

Perhaps the most important practical change is the requirement to demonstrate progress made since Phase 3.

Organisations must now include detailed information within both the ESOS Report and Notification of Compliance describing the energy saving measures implemented during the compliance period.

For each measure, participants must provide:

• a description of each measure,
• the energy savings achieved by each measure, and
• the category of savings, such as behavioural change, training or capital investment, etc.

Importantly, this information will not be published, but it must be included within the compliance documentation submitted to the regulator.

This marks a shift from simply identifying opportunities towards evidencing tangible improvements in energy performance.

4. Mandatory review of the Phase 3 Action Plan

Any organisation that was required to comply with ESOS Phase 3 must now review its previous Action Plan as part of the Phase 4 assessment.

The review requires organisations to identify:

• measures that were proposed but not implemented, and
• the reasons why those measures were not delivered.

The intention is to provide greater accountability and help government better understand barriers to implementing energy efficiency projects. The shared information will not be publicly available.

5. Lead Assessor notification

Lead Assessors must now notify their approved professional body each time they complete or review an ESOS assessment. This includes providing the participant’s contact details so the professional body can request to obtain the ESOS Report and evidence pack from the participant for quality assurance purposes.

The lead assessor must provide the:

• date of completion
• registered name and address of the responsible undertaking
• name, postal address, email address and telephone number of 2 contacts for the responsible undertaking, one of whom must be a director (or equivalent) who confirms that the information required for the notification of compliance is correct

This strengthens oversight of the Lead Assessor registers and supports consistent assessment standards.

6. Enhanced Notification of Compliance

The Notification of Compliance now requires additional information that were only provided on voluntary basis in Phase 3, including:

• the total number of sites covered by energy audits,
• ISO 50001 certification details
• UK Standard Industrial Classification (UK SIC) codes only, replacing the international classification used previously.

These additions improve the consistency and quality of national ESOS data.

7. Improved evidence requirements

Phase 4 places greater emphasis on maintaining an accurate Evidence Pack. Organisations must retain clearer records of:

• data used for specific calculations, and in relation to these activities:
  • the calculation of total energy consumption over the 12-month reference period
  • the identification of areas of significant energy consumption
  • the energy audit, particularly the identification of energy saving opportunities
  • the calculation of the total or significant energy consumption, as applicable, broken down by organisational purpose
  • the calculations of energy intensity ratios attributable to each organisational purpose
  • the conversion (where applicable) of total energy consumption or significant energy consumption into kWh
  • the preparation of your ESOS report
  • the calculation of estimated energy savings since the previous compliance date
  • the preparation of your ESOS action plan
  • the preparation of your ESOS progress updates
• evidence of any ISO 50001 certification used
• written agreements relating to compliance in a group structure
• if applicable, a record of the lead assessor’s notification of whether the ESOS assessment meets the scheme requirements
• information recorded on estimation methods or alternative methods of analysis used
• ESOS report
• Information submitted in the notification of compliance
• Action plan
• progress updates
• calculation methodologies,
• assumptions,
• data sources,
• energy consumption data, and
• supporting evidence for reported savings.

For an illustrated comparison of differences between the Phase 3 and Phase 4 requirements, please see Annex A.

For detailed, step-by-step guidance on meeting the compliance requirements, please refer to the Energy Savings Opportunity Scheme (Amendment) Regulations 2026, and the Comply with the Energy Savings Opportunity Scheme (ESOS) Phase 4 Guidance and the relevant appendices published by the Environment Agency.

Stay up to date with the Environment Agency's Newsletters:

ESOS NEWSLETTER -> SEPTEMBER 2026 (ISSUE 45)

ESOS NEWSLETTER -> AUGUST 2026 (ISSUE 44)

ESOS NEWSLETTER -> AUGUST 2026 (ISSUE 43)

New PAS 51215 standards

On 7 February 2025 the British Standards Institution (BSI) published two new standards which were referenced in the government response to the ESOS consultation:

• PAS 51215-1:2025 Energy and decarbonization assessment – Part 1: Process – Specification
• PAS 51215-2:2025 Energy and decarbonization assessment – Part 2: Competencies of lead assessors and assessment teams – Specification

The existing competency standard, PAS 51215:2014 Energy efficiency assessment: Competence of a lead energy assessor – Specification, will continue to be used as the competency standard for ESOS lead assessors for Phase 4.

However, ESOS Participants are able to use these standards on a voluntary basis for ESOS compliance during Phase 4.  The new PAS 51215-2:2025 competency standard can also be used on a voluntary basis by organisations wanting to determine whether an assessor is suitable to carry out an assessment according to PAS 51215-1:2025.

Find a Lead Assessor

• Graeme Johnson
• Katie Elmer
• Neil Fright

View our entire list of ESOS Lead Assessors

Complaints Procedure:

1. If anyone wishes to complain (anonymously or otherwise) about the conduct of an EMA ESOS Lead Assessor/ Member / Subject Matter Experts/ Course Candidate/ Workshop Attendee, then they must do so in writing to EMA Membership Services Manager, Edita Krupova. This should be done in writing to Energy Managers Association, Suite 77, 95 Mortimer Street, London, W1W 7GB as well as via email to [email protected].
2. The subject of the complaint will be notified of the complaint and given thirty (30) days to respond in writing and by email to the complaint. This response should include any facts relating to the complaints and their preferred channel to be contacted through.
3. Following the thirty (30) day period, the Executive of the EMA will establish a short report of all the facts associated with the complaint and present this to the EMA Board of Directors.
4. The EMA Board of Directors or a subcommittee formed with respect to the complaint matter, will make a decision regarding the complaint and notify the subject of the complaint within ten (10) working days in writing and via email.

ESOS Forum and CPD

Join EMA dedicated forum focused on all aspects of compliance with the Energy Savings Opportunity Scheme (ESOS).

The EMA ESOS Forum is designed to support ESOS Lead Assessors, ESOS auditors, representatives from participating organisations, and professionals involved in enabling ESOS compliance. Operating as a collaborative working group, the forum promotes knowledge-sharing, best practice, and continuous improvement. Participation provides a platform for ESOS professionals to address challenges, exchange insights, stay informed on the latest regulatory and industry developments, and contributes towards Continuing Professional Development (CPD).

Visit ESOS Forum webpage to find out more HERE.