The ESOS scheme will operate in 4 yearly compliance phases.

The last date of each compliance phase (`the compliance date’) is the date by which all participants must have undertaken its ESOS Assessment and notified its compliance to the Environmental Agency (the Scheme Administrator).

The deadlines for registering with the scheme (‘qualification’) and then completing the activity (‘compliance’) are therefore as follows: All participants will have to participate in each of these phases (assuming they are still a ‘large undertaking’):

Table 1: ESOS phase timings

Phase        Qualification date:        Four-year compliance phase:        Compliance date:

Phase 1     31st Dec 2014              6th Dec 2011 – 5th Dec 2015         5th Dec 2015

Phase 2     31st Dec 2018              6th Dec 2015 – 5th Dec 2019         5th Dec 2019

Phase 3     31st Dec 2022              6th Dec 2019 – 5th Dec 2023         5th Dec 2023