ESOS Register

Become a Lead Assessor today

About Us

ESOSRegister is an Approved Register for Lead Assessors regulated by the Environment Agency. ESOSRegister is part of the quality focused Quidos group which strives to offer its members dedicated support and guidance within the energy assessment industry.

Please do not hesitate to contact our friendly team on 01225 667 570 (option 1) or at if you have any questions

What is ESOS?

The Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment scheme for organisations in the UK who meet the eligibility criteria. The UK Scheme Administrator is the Environment Agency and each of the four devolved nations have their own regulator.

Organisations that qualify for ESOS must undertake an ESOS assessment every four years. An ESOS assessment is an audit of the energy used by the organisation through their buildings, industrial processes and transport and is used to identify energy saving measures that the organisation can implement in order to reduce their energy costs and usage.

Phase 2 of ESOS finished on 5th December 2019 and was superseded by Phase 3 which runs until 5th December 2023.Please see the dates of the first four ESOS phases below:

Compliance PeriodQualification DateCompliance PeriodCompliance Date
131 December 2014From 17 July 2014* to 5 December 20155 December 2015
231 December 2018From 6 December 2015 to 5 December 20195 December 2019
331 December 2022From 6 December 2019 to 5 December 20235 December 2023
431 December 2026From 6 December 2023 to 5 December 20275 December 2027
For more information on ESOS and to view or download the regulations, please visit the ESOS section on the Government website,

Finding a Lead Assessor

If you are an ESOS participant and need to locate a qualified Lead Assessor to carry out your ESOS assessment please click the button below to be taken to our list of all of our registered Lead Assessors.

How to Apply

If you are a qualified ESOS Lead Assessor, we would love to welcome you to our register. In order to apply, please complete the application form on our Apply page in full and press “Submit” on the declaration page. Our team will then be in touch with you directly regarding the next steps of the application process.

If you have any questions please do not hesitate to contact us on 01225 667 570 or

ESOS Registration Prices

ESOS Registration Prices. After fulfilling all the requirements mentioned on our home page, assessors need to register with to become Lead Assessors.

Year 1



For all new Lead Assessors joining our scheme. The annual registration fee for the first year also includes an application processing fee

Annual Renewal



From the second year onwards, annual registration is priced at £250+VAT

Environment Agency ESOS Newsletters


ESOS Resources

Complying with Energy Savings Opportunity Scheme

Approaches to ESOS audits

A guide to implementing Energy Savings Opportunities

ESOS Compliance Audit need to know guide

ESOS Consultation final

Annex A - Summary report template

Environment Agency response to the ESOS ESP Consultation - December 2021

Annex 1 - proposed changes to Section D of Annex 2 to the ESP

Contact Us

Do you need some clarity on some of our products and services or are you looking to become a lead assessor either way we would love to help?

Call us on 01225 667570 (Option 1)

Or email us at