The ESOS Phase 4 deadline is 5 December 2027. We break down what qualifies, what has changed, and how to approach compliance without overpaying.
How do you turn compliance pressure into competitive advantage?
Most organisations see energy compliance as a burden. A cost to endure. A box to tick. But that thinking leaves real money on the table.
Before doing anything else, here is what we would recommend: bring together monitoring, design, delivery, and financing. No fragmented advice. No gaps. Coordinate every step.
What has changed in Phase 4?
- DECs and Green Deal Assessments are no longer accepted as standalone compliance routes
- You must now document and report progress against your Phase 3 action plan
- Annual progress updates are required post-submission with board sign-off
- Site audits can begin before the qualification date of 31 December 2026
- Net zero assessments have been postponed to Phase 5
Do you qualify?
You qualify if your organisation has 250 or more employees, or annual turnover above £44m and a balance sheet above £38m. If any company within a UK group qualifies, the entire UK group must comply.
Why start now?
Organisations that start early identify real savings in 2026 and bank them. Lead assessors get booked up fast. Board sign-off takes longer than you think. And Phase 3 progress gets harder to reconstruct the longer you wait.
Turn your compliance obligations into practical progress and real savings. Because compliance is not the enemy - it is the catalyst for measurable change.
Need Help?
Our CIBSE-accredited engineers handle everything
From scoping to submission, we make sure the audit delivers real savings, not just a report.