ESOS is the Energy Saving Opportunitys Scheme and is a mandatory energy assessment scheme for organisations in the UK that meet the qualification criteria. The current criteria is for any UK company that either employs 250 or more people has an annual turnover in excess of 50 million euro (approx. £38,937,777) and an annual balance sheet total in excess of 43 million euro (approx. £33,486,489). The legislation also applies to an overseas company with a UK registered establishment which has 250 or more UK employees (paying income tax in the UK)/
Organisations that qualify for ESOS must carry out an assessment every 4 years. This assessment is an audit of the energy used by their buildings, industrial processes and transport to identify cost-effective energy saving measures. Organisations must notify the Environment Agency by a set deadline that they have complied with their ESOS obligations. The deadline for the first compliance period was 5th December 2015. The next ESOS compliance date is 5th December 2019.