ESOS Phase 4 for property groups and funds: settle the group map and the energy data first

The rules fit on a page. The time goes on structure, supplies and sign-off, and that’s where property owners get caught out.

For most property groups, the hard part of ESOS Phase 4 isn’t reading the rules. It’s answering three practical questions with evidence: which entities are in the group, which energy the group actually counts, and who signs off what. Groups that settle those early spend the compliance window on savings opportunities. Groups that don’t spend it rebuilding spreadsheets.

This article starts with the qualification test, then sets out those questions as governance and data tasks. Check the details against the current GOV.UK and Environment Agency guidance, linked below.

Do you qualify for Phase 4?

Phase 4 turns on one date. You’re in if, on 31 December 2026, your UK undertaking, or any UK undertaking in its group, is a “large undertaking”. That means it either:

• employs 250 or more people, or
• has annual turnover over £44 million and an annual balance sheet total over £38 million. Both figures have to be over the line.

Three details catch people out:

• Which accounts. Use the year ending on 31 December 2026, or the year ending in the 12 months before it, and test each undertaking rather than the consolidated figures alone.
• Who counts. Employees, owners, managers and partners, including part-time staff, taken as a monthly average rather than the headcount on 31 December.
• One year isn’t decisive. Size status only changes after two consecutive accounting periods on the other side of the line, so a long-standing large business that dips under once in 2026 is still in.

Keep three dates apart: 5 December 2026 for any Phase 3 progress update (a separate filing), 31 December 2026 for Phase 4 qualification, and 5 December 2027 to notify Phase 4 compliance in MESOS. Shrinking after 31 December 2026 doesn’t take you out.

Start with the group map

ESOS qualification is tested on each UK undertaking, and grouping follows company-law parent and subsidiary tests. For property businesses, that creates some familiar traps:

• One qualifying UK member can bring the whole group in, including SPVs that would be out on their own.
• The highest UK parent normally notifies, unless a written agreement in the evidence pack says otherwise. Splitting the work isn’t an exemption.
• UK establishments of overseas companies can be caught through the wider group.
• Fund and trust structures have their own treatment in the Phase 4 guidance, covering trustees, operators and fund managers. Read it against your actual structure rather than assuming.

So the first piece of evidence is a group map: every UK undertaking, its parent, the assets it holds, and the result of the size test for each, with the accounts it was based on.

Then decide whose energy it is

ESOS counts energy the group is supplied with and also consumes. For a landlord, that’s where most of the judgement sits:

• Energy recharged to tenants, whether measured or estimated, generally comes out.
• On multi-let buildings, someone has to agree and record who controls each supply.
• Assets bought and sold during the phase need a clear rule for inclusion.

The best way to make that defensible is a supply register: every meter, who procures it, who consumes it, whether it’s recharged, and how the recharge is measured. With that in place, the total is a calculation rather than a negotiation.

Choose the compliance route early

Most groups will need an ESOS assessment led by a lead assessor from an approved register, with site visits. Some will rely partly on ISO 50001. Either way, the work needs booking well ahead, because site visits across a portfolio take time to schedule and the data has to be ready before the assessor arrives.

Treat action plans as live commitments

Since Phase 3, qualifying groups have had to submit action plans and report progress against them. From Phase 4, the assessment itself has to cover that progress and explain anything that wasn’t delivered. That makes the opportunities register a governance document. Each opportunity needs an owner, a status and evidence, kept up during the year rather than reconstructed at the end.

A short checklist for the board

1. Is there a current group map, with the size test recorded for each UK undertaking?
2. Is there a supply register that separates landlord energy from tenant recharges?
3. Has the compliance route been agreed, and is the lead assessor booked?
4. Does every action-plan commitment have an owner and evidence?
5. Who signs the notification, and have they seen the evidence pack?

Where NZC Portal Ltd fits

The ESOS Phase 4 assessment module from NZC Portal Ltd is built for this work: organising the group, the energy data and the opportunities in one governed record, so the assessment starts from checked data. A director still signs the notification. The platform doesn’t submit to the government’s ESOS system for you. It keeps the evidence your assessor and directors are signing.

Because ESOS and SECR draw on much of the same energy data, groups can start with compliance and add reporting modules as they go, rather than collecting the same numbers twice.

See how NZC Portal Ltd organises ESOS evidence across a property group: nzcportal.co.uk/demo

General guidance only. It doesn’t determine whether your group qualifies for ESOS and isn’t legal advice. Check the current GOV.UK guidance for qualification tests and dates.

Sources: ESOS: find out if you qualify and how to comply (GOV.UK) · How to comply with ESOS Phase 4 (Environment Agency)