Energy Savings Opportunity Scheme (ESOS)

ESOS is a mandatory energy assessment scheme for large organisations in the UK.  It requires organisations to identify cost-effective energy efficiency opportunities that can both help reduce energy use and save money.

Do I qualify?

Organisations must take part in ESOS if on 31 December 2014 they, or at least one of their group members, were a 'large undertaking'*.

A 'large undertaking' is an organisation which:

  • is registered in the UK and employs at least 250 people; or
  • is registered in the UK and has an annual turnover above £38,937,777 and an annual balance sheet total above £33,486,489; or
  • is an overseas company with a UK registered establishment which has at least 250 UK employees (paying income tax in the UK)

ESOS does not apply to the public sector. 

*If your organisation is on the cusp of qualification and have recently grown or shrunk in size, please read the ESOS guidance at  It provides additional information which will help you determine qualification.

Act now, if you haven’t done so already

Complying with ESOS may take your organisation time, so it is important to act now to understand your responsibilities and determine what you need to do to comply.

ESOS assessment and first notification deadline

If your organisation qualifies, you need to complete your ESOS assessment of your energy use (processes, buildings, transport) and notify your compliance to the Environment Agency by 5 December 2015, and every 4 years thereafter.

There are no administrative fees and you do not need to register before submitting your notification.  The notification form can be accessed via the ESOS page on GOV.UK. 

Help and advice

If you have any further queries please contact the ESOS helpdesk at

Jo Scully – ESOS Project Manager, Environment Agency

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