ESOS Phase 4: the dates and who qualifies
The Energy Savings Opportunity Scheme runs in four-year phases, and Phase 4's two dates are close: qualification is tested on 31 December 2026, and the compliance notification is due by 5 December 2027.
Published 18 September 2026.
Who qualifies
On the qualification date, an organisation is in if it has 250 or more employees, or turnover over £44m together with a balance sheet total over £38m. Group rules apply: if one UK group member qualifies, the whole group participates. Qualification is by size, not by energy use — an office business with 250 employees and modest consumption still qualifies, though very low energy users have simplified routes to compliance.
Note that these are different figures from SECR's (250 employees, £36m turnover, £18m balance sheet, two of three) and from the Companies Act size limits. The 250-employee line appears in several regimes with different financial companions, which is why companies regularly owe one and not another.
What compliance involves
An energy audit covering at least 90% of total energy consumption, including transport; review by a lead assessor on an approved register; confirmation by a board-level director (two directors if the lead assessor is your own employee); an ESOS action plan with annual progress updates; and a compliance notification to the Environment Agency. The exception to the assessor requirement is an organisation whose energy use is fully covered by a certified ISO 50001 system.
Where we fit, honestly
ESOS sign-off needs a registered lead assessor, and software cannot be one — anyone who tells you otherwise is selling something the scheme does not allow. What we do is the data: the metered gas and electricity, fuel and transport records an ESOS audit consumes are the same records behind your SECR disclosure and your carbon footprint. Collect them once with every figure traceable to its source, and the audit gets cheaper, the assessor asks fewer questions, and the other duties fall out of the same dataset. For the assessment itself, we work with partner lead assessors.
Find out where you stand before the qualification date. The free duty check tests ESOS, SECR, PPN 006 and the climate-disclosure rules from one set of figures, naming the rule behind each verdict.
Sources
General information, not legal, accounting or assurance advice. Privacy · Terms