ESOS · After notification
ESOS action plans and progress updates
An ESOS action plan is the list of energy-efficiency measures an organisation commits to after notifying compliance, and progress updates report each year on what it actually did (SI 2014/1643 Part 6A).
For Phase 4 the plan is due by 5 December 2028, and there are now three progress updates rather than two, the last by 5 December 2031 (SI 2026/701 reg 28).
This page sets out who owes them, what goes in each, and what happens if they are missed.
Who owes one
Every notifier, whichever route it used
Regulation 34A(1) is short: following a notification of compliance under regulation 29(1), “the responsible undertaking must produce an ESOS action plan” (Part 6A).
That covers an organisation that used an energy audit and one that relied on ISO 50001, because both notify under regulation 29(1).
The only carve-out, inserted by SI 2026/701 regulation 27, is for a participant deemed compliant under regulation 33A because its consumption was zero.
The duty arrived with the 2023 amendment regulations, in force on 29 November 2023, so Phase 3 was the first phase to carry it.
Whether you are in ESOS at all is covered on ESOS Phase 4, and the assessment that comes first on ESOS compliance.
A participant whose total energy consumption is zero kWh is deemed compliant with Part 6A under regulation 33A.
It notifies, and owes no action plan and no progress updates.
ESOS action plan deadline
Four windows, each ending on 5 December
The windows are set by the regulation, not by the regulator.
An action plan must be notified between the first day of the next compliance period and the day before its first anniversary; for Phase 4 that is 6 December 2027 to 5 December 2028.
Each progress update then has its own one-year window, running from the first, second and third anniversaries of that first day.
So an update notified early, before its window opens, is not a progress update for that window.
Phase 3 is still running: its statutory action plan deadline was 5 December 2024, the Environment Agency accepted plans until 5 March 2025, the first progress update was due by 5 December 2025, and the second is due by 5 December 2026 (GOV.UK).
The Environment Agency’s Phase 4 guidance says in places that updates are due “in 2029 and 2030”; the amended regulation requires a third in 2031, and the regulation governs.
Phase 4
- 5 Dec 2027Notification of compliance
The trigger for everything below.
- 5 Dec 2028Action plan
Window 6 Dec 2027 – 5 Dec 2028.
- 5 Dec 2029Initial progress update
Window 6 Dec 2028 – 5 Dec 2029.
- 5 Dec 2030Further progress update
Window 6 Dec 2029 – 5 Dec 2030.
- 5 Dec 2031Final progress update
New in Phase 4; window 6 Dec 2030 – 5 Dec 2031.
What goes in an ESOS action plan
Six items per measure, or a nil statement
| Item | What regulation 34A requires | Paragraph |
|---|---|---|
| The measure | Each measure to improve energy efficiency the participant proposes to implement before the end of the next compliance period | 34A(3)(a)(i) |
| Its origin | Whether an energy audit recommended it | 34A(3)(a)(ii) |
| Its date | The date by which the participant proposes to implement it | 34A(3)(a)(iii) |
| Total savings | An estimate of the total energy savings it reasonably expects over the period, in kWh | 34A(3)(a)(iv) |
| Savings by purpose | How much of that saving falls in each organisational purpose, in kWh | 34A(3)(a)(v) |
| Method | The method used for the estimate | 34A(3)(a)(vi) |
| — or — | A statement that there is no measure the participant proposes to implement | 34A(3)(b) |
| Estimate basis | Whether the estimate comes from the energy audit, from a deemed-compliance route, or from another reasonable method | 34A(4) |
| Other methods | A brief description of the method and the reason for it, recorded in the evidence pack | 34A(5) |
| Confirmation | That the responsible officer is satisfied the plan complies and has seen and considered it | 34A(8) |
The four organisational purposes are transport, industrial processes, buildings and any other purpose, so a measure’s saving is split between them.
There is no statutory requirement to state a cost, a payback period or an investment figure, though many plans record them for their own use.
A measure does not have to come from the audit; the plan says whether it did.
A nil plan is lawful, and it is published like any other.
ESOS progress report
What each progress update must record
A progress update is “a written record identifying any action taken … since the relevant event to implement measures to improve the participant’s energy efficiency” (reg 34B(2)).
The relevant event for the first update is the action plan’s notification; for each later update it is the previous update’s.
It reports against the latest action plan, measure by measure, and gives an estimate of the energy saved in the reporting period, in kWh since 22 July 2026.
The estimate can come from the audit, from the figure in the plan, or from another reasonable method, and the update must say which.
The third, final update exists only for compliance periods ending on or after 5 December 2027, so Phase 3 has two and Phase 4 three.
The table beside this section is a working layout of the required content; the update itself is submitted through MESOS.
| Field | Regulation 34B |
|---|---|
| Measures implemented since the last submission | (3)(a)(i) |
| Whether each met its planned date | (3)(a)(ii) |
| Measures not implemented by their planned date | (3)(a)(iii) |
| Energy reduction in the period, in kWh | (3)(b) |
| Method used for that estimate | (3)(c) |
| Estimate basis: audit, the plan, or another method | (4) |
| Responsible officer confirmation | (7) |
The loop closes
The next ESOS report reviews the plan
Phase 4 added an action plan review to the ESOS report: it must identify measures from the current plan that have not been implemented and are not expected to be, and explain why (SI 2026/701 reg 17, new reg 27E).
The Environment Agency’s report checklist adds that, where applicable, the report must confirm the participant did not produce an action plan it was required to produce.
The ESOS report must also state the energy savings actually achieved in the compliance period, per measure in kWh.
What is published differs by item: action plans and progress updates are published, the combined kWh saving achieved is published, and the action plan review narrative is not.
If one is missed
No penalty in the regulations, but a public record
Part 8 of the regulations sets penalties for failing to notify, keep records, undertake an assessment, obey a notice, or tell the truth; it names neither regulation 34A nor 34B (Part 8).
The Environment Agency’s guidance says the same in its own words: regulators will not take enforcement action or issue a penalty for non-submission of an action plan or progress update, but the failure will be published.
So the absence of a penalty is a gap in the statute, not only a policy of forbearance.
The consequence is reputational: the published record shows who did not submit.
A regulator can serve an enforcement notice under regulation 38.
Failing to comply with that notice is penalisable under regulation 46: up to £5,000 plus £500 per working day, for up to 80 working days.
What Phase 3 shows
The first round, in the published data
The Environment Agency’s published Phase 3 data is the only evidence of how the new duties are being met.
Our count of the workbooks, as at the 5 June 2026 data cut, finds 7,062 published action plans and 5,609 first progress updates.
Of the updates with a readable submission date, 80.6% were filed in the final 30 days and 11.2% after the 5 December 2025 deadline.
About a quarter of the measures listed in those updates were marked as implemented.
These are counts from Phase 3 data; Phase 4 publishes a different set of fields, so they should not be read forward as a prediction.
The ESOS and SECR hub connects the plan’s measures to the energy-efficiency narrative a company already writes each year under SECR.
Frequently asked
ESOS action plans: questions people ask
What is an ESOS action plan?
A written record, notified to the Environment Agency through MESOS, setting out each energy-efficiency measure the organisation proposes to implement in the next compliance period, whether an energy audit recommended it, the date it will be implemented, the estimated energy savings in kWh in total and for each organisational purpose, and how the estimate was made. An organisation proposing no measures says so instead.
When is the ESOS action plan deadline?
For Phase 4 the plan must be notified within the year beginning 6 December 2027, so by 5 December 2028. For Phase 3 the statutory deadline was 5 December 2024, and the Environment Agency accepted plans until 5 March 2025.
Who has to submit an ESOS action plan?
Every responsible undertaking that notifies compliance under regulation 29(1) must then produce one, whichever route it used, including ISO 50001. The only exception in the regulation is a participant with zero energy consumption that is deemed compliant under regulation 33A.
What is an ESOS progress update, or progress report?
A written record of the action taken since the last submission: which measures from the action plan have been implemented and whether on their planned dates, which have not, and an estimate in kWh of the reduction in energy consumption in the period, with the method used. It is notified through MESOS within its one-year window.
How many ESOS progress updates are there in Phase 4?
Three, due by 5 December 2029, 5 December 2030 and 5 December 2031. The third, the final progress update, was added by regulation 28 of SI 2026/701 for compliance periods ending on or after 5 December 2027. Parts of the Environment Agency’s own guidance and older GOV.UK pages still say two; the regulation says three.
Is there a penalty for missing an ESOS action plan or progress update?
No penalty is set in the regulations: Part 8 names no offence for regulations 34A or 34B, and the Environment Agency’s guidance says regulators will not take enforcement action or issue a penalty for non-submission. The scheme administrator publishes the failure instead. If a regulator served an enforcement notice requiring a submission, failing to comply with that notice would be penalisable.
Are ESOS action plans published?
Yes. The regulations require the scheme administrator to publish each action plan and each progress update. The action plan review in the next ESOS report, the list of measures not implemented and the reasons, is not published.
Is there an ESOS progress update template?
The regulation sets the content and submissions are made through MESOS, the Environment Agency’s notification system. This page lays the required content out as a table you can use to prepare the figures before you submit.
Who signs off an ESOS action plan?
The notification must confirm that the responsible officer is satisfied the requirements have been met and has seen and considered the plan. The regulations require one or two responsible officers for the ESOS assessment depending on the lead assessor’s independence, but they do not state a number for action plans or progress updates.
Sources
Primary sources
Every figure, date and status on this page traces to the instrument’s owner. Secondary commentary is never the source for a number.
- legislation.gov.ukSI 2014/1643, Part 6A — ESOS action plan (reg 34A) and progress update (reg 34B), as consolidated
The contents, windows and confirmations, with the 2026 amendments applied.
- legislation.gov.ukSI 2014/1643, regulation 34A — ESOS action plan
The provision page; cite the Part 6A page for the kWh wording.
- legislation.gov.ukSI 2023/1182, regulation 26 — inserting Part 6A
Action plans and progress updates created, in force 29 November 2023.
- legislation.gov.ukSI 2026/701, regulation 27 — amending reg 34A
kWh estimates; zero-kWh participants excluded (reg 34A(11)).
- legislation.gov.ukSI 2026/701, regulation 28 — the final progress update
Third progress update for compliance periods ending on or after 5 December 2027.
- legislation.gov.ukSI 2014/1643, regulation 33A — zero energy consumption
Deemed compliance with Part 6A for a zero-kWh participant.
- legislation.gov.ukSI 2014/1643, Part 8 — civil penalties
No offence attaches to regulations 34A or 34B.
- legislation.gov.ukSI 2026/701 (as made)
Reg 17 (the action plan review, reg 27E) and reg 31 (what is published).
- Environment AgencyHow to comply with ESOS phase 4 (30 July 2026)
The action plan and progress update chapters; the no-penalty statement; the Phase 3 dates.
- Environment AgencyAppendices A1 and A2: report checklists for participants
The action plan review checklist for the next ESOS report.
- Environment AgencyESOS: find out if you qualify and how to comply
Phase 3 second progress update due 5 December 2026.
- Environment Agency, via data.gov.ukEnergy Savings Opportunity Scheme — published data (Phase 3)
Published action plans and first progress updates, 5 June 2026 data cut.