Skip navigation

Power resilience for a net zero world

Contact Us


Energy Savings Opportunity Scheme (ESOS)

ESOS was introduced in 2014 to ensure large enterprises in the UK are energy efficient. Organisations that meet the qualification criteria are required to carry out a mandatory energy assessment every four years, with the intention of finding new ways to save energy. These assessments must be carried out during each official ESOS phase by an approved ESOS Lead Assessor.

An ESOS report will measure the energy consumption of buildings, transport and processes.

Organisations that are required to carry out ESOS assessments are those that meet the following criteria, as of the qualification date for each phase:

  • Over 250 employees in the UK or
  • An annual turnover exceeding €50m (£44.1m) or
  • A balance sheet exceeding €43m (£37.9m)

Organisations subject to the Public Contracts Regulations (2006) are exempt.

The four currently laid out phases of ESOS are as follows:

Qualification Date
Compliance Period
Compliance Date
31 December 2014
17 July 2014 – 5 December 2015
5 December 2015
31 December 2018
6 December 2015 – 5 December 2019
5 December 2019
31 December 2022
6 December 2019 – 5 December 2023
5 December 2023
31 December 2026
6 December 2023 – 5 December 2027
5 December 2027

An ESOS assessment will require 12 consecutive months of total consumption data, including the qualification date but not the compliance date. Energy covered by ISO 5001 is not required to be assessed. Once reviewed by a Lead Assessor to verify compliance, ESOS assessments are signed off at board member or director level within an organisation, usually by the managing director or finance director.

The ESOS scheme is managed by the Environment Agency in England, the Northern Ireland Environment Agency, the Scottish Environment Protection Agency and Natural Resources Wales.

Qualifying organisations who fail to meet compliance deadlines are liable for a fine of £50,000, plus an additional fine of £800 per day up to a maximum of 80 days. False or misleading records can also result in a £50,000 fine.

Contact our team to see how we can help you achieve your business’s energy objectives, save money and achieve net-zero.

Contact Us And Find Out More


This website uses cookies. You can read more information about why we do this, and what they are used for here.

Accept Decline