The official deadline for ESOS Phase 4 compliance is 5 December 2027, but don’t be fooled into thinking this is a problem for the distant future. There is plenty to be getting on with during 2026, and the organisations that plan ahead will find the process far less stressful, and far more valuable. Even if your organisation doesn’t strictly need to comply with ESOS, independent energy audits can still deliver real benefits, from identifying cost savings to supporting grant applications. Here’s your practical ESOS to-do list for 2026.
- Dealing with Late Submissions (Phase 3)
Hopefully, most Phase 3 submissions are now behind us. However, if the regulator has been in touch about a late or missing submission, it’s important to act quickly. Engaging an ESOS Lead Assessor is usually the best first step. It demonstrates intent, provides a clear pathway to compliance, and can help prevent fines from escalating, which they can do very quickly for ongoing non-compliance. Action Plans and Progress Updates should also have been submitted by now. These cannot be completed on the MESOS system until the Phase 3 compliance notification has been filed. While there are no financial penalties for submitting Action Plans or Progress Updates late, failing to submit them will place your organisation on a public register showing that no energy efficiency actions are being taken. This may not be a regulatory fine, but it can carry reputational and commercial risks.
- Progress Update 2 – Deadline: 5 December 2026
This is a key milestone for 2026. By 5 December 2026, organisations must submit Progress Update 2, reporting on the energy savings achieved through implemented energy reduction measures. A Lead Assessor is not required for this submission, but many organisations choose to work with one — particularly if their implemented actions go beyond the recommendations in the original ESOS report.
- Qualification Date – 31 December 2026
The qualification date for ESOS Phase 4 is 31 December 2026. Any Phase 4 submission must include 12 months of energy data that covers this date. In theory, this means that if your energy audits are already completed, you could submit your Phase 4 compliance as early as the first working day of 2027. That’s a powerful incentive to get organised early.
- Start Energy Audits in 2026
If you want to get ahead of the curve, 2026 is the ideal time to start site energy audits.
Doing so:
- Reduces pressure as the compliance deadline approaches
- Identifies cost-effective energy saving measures sooner
- Allows you to implement changes earlier and start saving earlier
In practice, we typically identify energy savings worth at least three times our fee, making audits a commercial opportunity rather than just a compliance exercise.
- ESOS Phase 4: What’s Changing?
According to the Government website, the following changes are intended to apply to Phase 4, subject to parliamentary time and scrutiny:
- Removal of Display Energy Certificates (DECs) and Green Deal Assessments (GDAs) as compliance routes
- Progress against Action Plan commitments to be included in the ESOS assessment
- Explanations required where Action Plan commitments have not been met
These changes place greater emphasis on action, delivery, and accountability, rather than compliance being a purely reporting exercise.
Making Phase 4 Painless — and Valuable
ESOS doesn’t have to be a box-ticking exercise. With the right planning, it can be a powerful driver of cost savings, operational efficiency, and carbon reduction.
If you’d like to make your ESOS Phase 4 journey painless and effective, feel free to get in touch for an informal chat: https://shiftenvironment.co.uk/contact/