Back in 2021, the Government carried out a detailed consultation regarding changes to the Energy Savings Opportunity Scheme (ESOS). When the Government provided a response to the consultation in July 2022, they announced several changes in phase 3, many of which were implemented before the phase ended, and phase 4, which is the current ESOS phase.
One of the proposed Phase 4 changes was the intended refocus of ESOS so that it covered both energy and net zero, with net zero assessments requiring confirmation that ESOS recommendations are aligned to net zero goals. It was expected that the net zero assessments would provide information to help organisations put together a net zero plan or to help them meet existing plans.
However, given that some Phase 3 changes and guidance ended up delayed, and in order to give more time for organisations to adapt to the ESOS changes already in place, the Government has decided to postpone the introduction of net zero requirements in ESOS until Phase 5 (beginning on 6 December 2027 with a compliance date of 5 December 2031). It is recognised, though, that some ESOS participants might already be carrying out some elements of a net zero assessment. As a result, the Government has been working with BSI to finalise PAS standards which can be used on a voluntary basis for ESOS in Phase 4. The following PAS standards have been published for this purpose:
Any participant wanting to show their commitment to net zero can use the PAS 51215-1:2025 to carry out assessments covering emissions related to energy covered by ESOS. It can also be used to assess governance and risks related to achieving net zero across those emissions, as well as to propose how net zero can be achieved by 2050 across those emissions. Further guidance will be published on this in due course.
In addition, the Government will not align the ESOS qualification thresholds with the thresholds set for Streamlined Energy and Carbon Reporting (SECR) in Phase 4. This will remain in consideration but, for now, it hasn't been confirmed whether the threshold change is intended for Phase 5.
Whilst those two big changes will not be introduced in Phase 4, the Government has confirmed it will go ahead with some smaller Phase 4 changes, as previously intended. As it stands, the Government hopes to introduce these changes by the beginning of 2027, in advance of the Phase 4 compliance deadline on 5 December 2027. The changes are:
Further updates on these proposed Phase 4 changes will be made in due course, with legislation and updated guidance planned for early 2027. In addition, changes to the 'Manage your Energy Savings Opportunity Scheme (MESOS)' system will be made to accommodate the changes.
For more information, see the:
